The document discusses different types of forces including contact forces, non-contact forces, frictional forces, and buoyant forces. It defines force as a push or pull that can change the motion of an object. There are two main types of forces - contact forces that act directly between objects in contact, and non-contact forces that act over a distance through force fields. Examples of both types are given. Frictional forces oppose the relative motion of objects in contact and can be useful or disadvantageous depending on the situation. The coefficient of friction and methods for measuring it are also described.
This document provides an overview of key concepts in strength of materials including:
- Stress is defined as the internal resisting force induced per unit area when an external force is applied. The two basic types of stress are normal stress and shear stress.
- Strain is the ratio of deformation to original dimension when a body undergoes stress. The main types of strain are longitudinal, lateral, normal, tensile, compressive, and shear.
- Hooke's law states that within the elastic limit, stress is directly proportional to strain for a material. When stress is applied and removed, elastic materials will return to their original state.
This document discusses buoyancy, floatation, and the equilibrium of submerged and floating bodies. It defines buoyancy as the upward force that opposes gravity when an object is immersed in a fluid. Archimedes' principle states that the buoyant force is equal to the weight of the fluid displaced by the object. The point where the buoyant force is applied is called the center of buoyancy. For a floating body to be in stable equilibrium, the metacenter must be above the center of gravity. The distance between these two points is called the metacentric height.
The document provides an overview of a physics lesson on friction that includes taking notes on friction, completing a worksheet, and conducting a lab experiment to determine the coefficient of friction of a shoe. Students are instructed to get their materials ready, answer warm-up questions about friction in soccer, and learn key concepts such as friction forces, the normal force, and how to calculate the coefficient of static friction.
- The document provides instructions for a physics class, including taking notes on friction and completing an assignment.
- It discusses friction as a force that resists the motion of objects in contact and defines key terms like normal force and coefficient of friction.
- It presents an example calculation of the coefficient of sliding friction using the weight of a shoe and the force required to make it slide.
This document provides an overview of buoyancy and stability of floating bodies. It defines key concepts such as buoyant force, Archimedes' principle, and stability. The main points are:
- Buoyant force is the upward force a fluid exerts on a body immersed in it, caused by increased pressure with depth. By Archimedes' principle, the buoyant force equals the weight of the fluid displaced by the body.
- For a body to float, its weight must equal the buoyant force (weight of displaced fluid). A body will sink, float, or remain at rest depending on its average density compared to the fluid.
- Stability depends on the alignment of the center
Equilibrium requires that the sum of all forces and sum of all moments acting on an object are equal to zero. Static equilibrium is maintained when the external forces give a zero resultant force and zero total moment. Additional concepts important to equilibrium include the center of mass, hydrostatics, friction, and moments of force.
Lesson 2_ effects of forces.pptx about forces and its effectsmadonnasibrahim
ย
Forces can cause objects to change motion, speed, direction or shape. A force is a push or pull that can be measured in Newtons, though forces cannot be seen directly. This document discusses different types of forces including gravity, friction, air resistance, upthrust and how forces affect objects. It provides examples of how pushing and pulling change the motion and shape of objects. An experiment is described to measure the difference between an object's weight in air and water, and how upthrust causes the weight to be less in water.
This document provides an overview of key concepts in strength of materials including:
- Stress is defined as the internal resisting force induced per unit area when an external force is applied. The two basic types of stress are normal stress and shear stress.
- Strain is the ratio of deformation to original dimension when a body undergoes stress. The main types of strain are longitudinal, lateral, normal, tensile, compressive, and shear.
- Hooke's law states that within the elastic limit, stress is directly proportional to strain for a material. When stress is applied and removed, elastic materials will return to their original state.
This document discusses buoyancy, floatation, and the equilibrium of submerged and floating bodies. It defines buoyancy as the upward force that opposes gravity when an object is immersed in a fluid. Archimedes' principle states that the buoyant force is equal to the weight of the fluid displaced by the object. The point where the buoyant force is applied is called the center of buoyancy. For a floating body to be in stable equilibrium, the metacenter must be above the center of gravity. The distance between these two points is called the metacentric height.
The document provides an overview of a physics lesson on friction that includes taking notes on friction, completing a worksheet, and conducting a lab experiment to determine the coefficient of friction of a shoe. Students are instructed to get their materials ready, answer warm-up questions about friction in soccer, and learn key concepts such as friction forces, the normal force, and how to calculate the coefficient of static friction.
- The document provides instructions for a physics class, including taking notes on friction and completing an assignment.
- It discusses friction as a force that resists the motion of objects in contact and defines key terms like normal force and coefficient of friction.
- It presents an example calculation of the coefficient of sliding friction using the weight of a shoe and the force required to make it slide.
This document provides an overview of buoyancy and stability of floating bodies. It defines key concepts such as buoyant force, Archimedes' principle, and stability. The main points are:
- Buoyant force is the upward force a fluid exerts on a body immersed in it, caused by increased pressure with depth. By Archimedes' principle, the buoyant force equals the weight of the fluid displaced by the body.
- For a body to float, its weight must equal the buoyant force (weight of displaced fluid). A body will sink, float, or remain at rest depending on its average density compared to the fluid.
- Stability depends on the alignment of the center
Equilibrium requires that the sum of all forces and sum of all moments acting on an object are equal to zero. Static equilibrium is maintained when the external forces give a zero resultant force and zero total moment. Additional concepts important to equilibrium include the center of mass, hydrostatics, friction, and moments of force.
Lesson 2_ effects of forces.pptx about forces and its effectsmadonnasibrahim
ย
Forces can cause objects to change motion, speed, direction or shape. A force is a push or pull that can be measured in Newtons, though forces cannot be seen directly. This document discusses different types of forces including gravity, friction, air resistance, upthrust and how forces affect objects. It provides examples of how pushing and pulling change the motion and shape of objects. An experiment is described to measure the difference between an object's weight in air and water, and how upthrust causes the weight to be less in water.
This document discusses key concepts in fluid mechanics, including:
1) Fluid statics, hydrostatic equilibrium, Archimedes' principle, and buoyancy.
2) Fluid dynamics principles like conservation of mass expressed by the continuity equation, and conservation of energy expressed by Bernoulli's equation.
3) Applications of fluid dynamics concepts like calculating flow rates and velocities using the continuity equation, and calculating velocities using Bernoulli's equation.
Forces can push or pull on objects and change their motion. A force is measured in Newtons. The net force on an object determines its acceleration according to F=ma. Newton's three laws describe how forces interact: 1) objects in motion stay in motion unless a force acts; 2) F=ma; 3) for every action there is an equal and opposite reaction. Centripetal force provides the inward pull that causes objects to travel in circular paths. Stability depends on the location of an object's center of mass relative to its base.
Forces can push or pull on objects and change their motion. A force is measured in Newtons. The net force on an object determines its acceleration according to F=ma. Newton's three laws describe how forces interact: 1) objects in motion stay in motion unless a force acts, 2) F=ma, and 3) for every action there is an equal and opposite reaction. Centripetal force provides the inward force needed for circular motion. Levers, moments, and fulcrums can be used to make work easier by reducing the needed force. The location of an object's center of mass determines its stability.
The document provides information about forces and work. It defines force as a push or pull and discusses different types of forces including gravitational, frictional, electrostatic, and magnetic forces. It also defines work as the product of the applied force and the distance moved, and power as the rate at which work is done. Methods for reducing friction like lubricants and ball bearings are presented. Examples of calculating work, power, and solving physics problems involving forces are also included.
This document provides an introduction to engineering mechanics from Baba Farid College of Engineering and Technology. It includes:
1) Biographical information about the instructor Parvinkal Singh Mann, who has worked in engineering education for many years and published over 20 research papers.
2) An overview of engineering mechanics, which involves the study of forces and their effects on bodies at rest (statics) and in motion (dynamics), and how it relates to other fields like kinematics and kinetics.
3) Definitions of key terms in mechanics like force, pressure, mass, weight, density, and others, and explanations of the differences between concepts like mass and weight.
Here are the answers:
1. Work = Force x Distance
= 50N x 10m
= 500 Joules
2. Work = Force x Distance
= Weight x Height
= 45 kg x 9.8 m/s^2 x 1.2m
= 546.4 Joules
3. Total Force = Tom's Force + Jerry's Force = 50N + 70N = 120N
Work = Total Force x Distance
= 120N x 4m
= 480 Joules
1) Force is an external agent that can change the motion or position of an object, and has both magnitude and direction. Forces can be balanced or unbalanced. Balanced forces do not change the motion of an object, while unbalanced forces do.
2) Graphs can represent motion, including distance-time graphs for objects with uniform or non-uniform speed, and velocity-time graphs for objects with uniform or non-uniform acceleration. Equations relate displacement, velocity, acceleration, and time for accelerated motion.
3) Newton's Three Laws of Motion describe how forces affect the motion of objects: an object at rest stays
The document describes various concepts related to forces including:
1) Different types of forces such as magnetic, weight, tension, contact, and friction forces.
2) The effects of forces including changing an object's motion, speed, direction, shape, and putting a stationary object into motion.
3) The relationship between net force, mass, and acceleration given by F=ma.
4) How to calculate weight, distinguish it from mass, and how it depends on gravitational strength.
This document provides information about force and pressure in physics for class 8. It discusses that force has magnitude and direction, is represented by an arrow, and does not affect the mass of an object. It also explains the turning effect of force, called moment, which depends on the force and perpendicular distance from the pivot point. Further, it defines pressure as the force per unit area and discusses how liquid pressure increases with depth due to the weight of the liquid above. Archimedes' principle of upthrust or buoyancy is also summarized.
This document provides an introduction to work, energy and power. It defines work as the product of force and displacement in the direction of force. Positive work is when force and displacement are in the same direction, while negative work is when they are in opposite directions. Kinetic energy is defined as half the mass times the velocity squared. The work-energy theorem states that work done equals the change in kinetic energy. Potential energy is the energy an object has due to its position or state. The conservation of mechanical energy principle applies to systems where only conservative forces act. It states the total mechanical energy of the system, which is the sum of kinetic and potential energy, remains constant. An example is provided of calculating work and energy for a
This document discusses key concepts relating to forces in physics. It defines a force as a push or pull and notes they can be measured in newtons. Balanced forces cause no acceleration while unbalanced forces produce changes in motion. Friction and air resistance are examples of contact forces. Hooke's law states the extension of a spring is proportional to the applied load. Newton's second law relates force, mass and acceleration using the equation F=ma.
This document discusses key concepts relating to forces in physics. It defines a force as a push or pull and notes they can be measured in newtons. Balanced forces will not cause a change in motion, while unbalanced forces will. Friction and air resistance are examples of contact forces. Hooke's law states the extension of a spring is proportional to the applied force. Newton's second law relates force, mass and acceleration using the equation F=ma.
Sehs 4.3โ biomechanics ii (4.3.3, force, com)strowe
ย
The document discusses the fundamentals of biomechanics, including forces and levers. It defines a force as a push or pull that acts on an object, and can be quantified by both magnitude and direction. Forces can be contact forces, which require touching the object, or long-range forces like gravity that act without contact. Levers are rigid bars that rotate around a fulcrum, and there are three classes of levers that differ based on the relative positions of the fulcrum, effort, and resistance. The center of mass of an object can change based on factors like body position, external loads, and age or sex, and affects an object's stability.
This document contains information about an introductory fluid mechanics course, including:
- The lecturer's name and contact information, as well as consultation hours for the lecturer and another professor.
- An outline of topics to be covered, including fluid motion, thermal physics, electricity, and revision.
- A brief overview of fluid properties like density, pressure, compressibility of gases, liquids and solids.
- Explanations of concepts like hydrostatic equilibrium, Pascal's law, Archimedes' principle, buoyancy, and the continuity equation.
- Examples of calculating pressure, buoyant force, and applying conservation of mass.
The bottles did not move because of inertia - their mass resists changes in motion. It is a real demonstration of inertia. To pull it off:
- The bottles are glued to the table, so they cannot slide when pushed.
- The person pushes on the table, not directly on the bottles, so the bottles feel less force than what appears.
- Quick camera cuts and angles are used to hide that the bottles are fixed in place. It's an illusion that fools the eye through clever filming.
So in summary, it uses inertia and camera tricks to create the illusion that the bottles are resisting the push through their own inertia alone.
This document defines force and gravity. It explains that force is a push or pull that can cause an object to change its motion or speed. There are different types of forces including contact forces like friction and non-contact forces like magnetic and gravitational forces. Gravity is the force of attraction between all objects with mass and the Earth. The center of gravity is the point where all of an object's weight can be considered to be concentrated. An object's stability depends on whether its line of gravity falls within the base of support.
This document provides definitions and explanations of basic biomechanical concepts including:
- Mass is the quantity of matter an object contains and is measured in kilograms. Weight is the force exerted on a surface due to gravity and is measured in kilograms-force.
- A force can produce movement or deformation and is measured in Newtons. Newton's laws of motion describe how objects interact under various forces.
- The centre of gravity is the point where total mass of an object is considered to be concentrated. An object's stability depends on the position of its centre of gravity relative to its base of support.
- Forces can be analyzed using graphical methods like the parallelogram and triangle methods
This document provides an overview of kinetics, including definitions of force, methods of calculating force, types of forces, force vectors, naming conventions for forces, and concepts related to force including gravity, equilibrium, and force systems. Specifically, it defines force as that which produces or modifies motion, discusses Newtons as a unit of force, and covers the two types of forces - external and internal. It also addresses centre of gravity, line of gravity, base of support, and their relationship to stability. The three types of equilibrium - stable, unstable, and neutral - are defined. Finally, it outlines the four types of force systems: linear, parallel, rotational, and concurrent.
Here are the steps to re-arrange the surfaces by slipperiness:
1. Ice
2. Wet Mud
3. Wet Grass
4. Thick Carpet
5. Wet concrete
6. Dry concrete
2. a. An ice skater performing a routine wants as little friction as possible.
b. A driver driving a car on a wet road wants as much friction as possible.
c. A mountain biker riding down a steep muddy hill wants as little friction as possible.
This document discusses key concepts in fluid mechanics, including:
1) Fluid statics, hydrostatic equilibrium, Archimedes' principle, and buoyancy.
2) Fluid dynamics principles like conservation of mass expressed by the continuity equation, and conservation of energy expressed by Bernoulli's equation.
3) Applications of fluid dynamics concepts like calculating flow rates and velocities using the continuity equation, and calculating velocities using Bernoulli's equation.
Forces can push or pull on objects and change their motion. A force is measured in Newtons. The net force on an object determines its acceleration according to F=ma. Newton's three laws describe how forces interact: 1) objects in motion stay in motion unless a force acts; 2) F=ma; 3) for every action there is an equal and opposite reaction. Centripetal force provides the inward pull that causes objects to travel in circular paths. Stability depends on the location of an object's center of mass relative to its base.
Forces can push or pull on objects and change their motion. A force is measured in Newtons. The net force on an object determines its acceleration according to F=ma. Newton's three laws describe how forces interact: 1) objects in motion stay in motion unless a force acts, 2) F=ma, and 3) for every action there is an equal and opposite reaction. Centripetal force provides the inward force needed for circular motion. Levers, moments, and fulcrums can be used to make work easier by reducing the needed force. The location of an object's center of mass determines its stability.
The document provides information about forces and work. It defines force as a push or pull and discusses different types of forces including gravitational, frictional, electrostatic, and magnetic forces. It also defines work as the product of the applied force and the distance moved, and power as the rate at which work is done. Methods for reducing friction like lubricants and ball bearings are presented. Examples of calculating work, power, and solving physics problems involving forces are also included.
This document provides an introduction to engineering mechanics from Baba Farid College of Engineering and Technology. It includes:
1) Biographical information about the instructor Parvinkal Singh Mann, who has worked in engineering education for many years and published over 20 research papers.
2) An overview of engineering mechanics, which involves the study of forces and their effects on bodies at rest (statics) and in motion (dynamics), and how it relates to other fields like kinematics and kinetics.
3) Definitions of key terms in mechanics like force, pressure, mass, weight, density, and others, and explanations of the differences between concepts like mass and weight.
Here are the answers:
1. Work = Force x Distance
= 50N x 10m
= 500 Joules
2. Work = Force x Distance
= Weight x Height
= 45 kg x 9.8 m/s^2 x 1.2m
= 546.4 Joules
3. Total Force = Tom's Force + Jerry's Force = 50N + 70N = 120N
Work = Total Force x Distance
= 120N x 4m
= 480 Joules
1) Force is an external agent that can change the motion or position of an object, and has both magnitude and direction. Forces can be balanced or unbalanced. Balanced forces do not change the motion of an object, while unbalanced forces do.
2) Graphs can represent motion, including distance-time graphs for objects with uniform or non-uniform speed, and velocity-time graphs for objects with uniform or non-uniform acceleration. Equations relate displacement, velocity, acceleration, and time for accelerated motion.
3) Newton's Three Laws of Motion describe how forces affect the motion of objects: an object at rest stays
The document describes various concepts related to forces including:
1) Different types of forces such as magnetic, weight, tension, contact, and friction forces.
2) The effects of forces including changing an object's motion, speed, direction, shape, and putting a stationary object into motion.
3) The relationship between net force, mass, and acceleration given by F=ma.
4) How to calculate weight, distinguish it from mass, and how it depends on gravitational strength.
This document provides information about force and pressure in physics for class 8. It discusses that force has magnitude and direction, is represented by an arrow, and does not affect the mass of an object. It also explains the turning effect of force, called moment, which depends on the force and perpendicular distance from the pivot point. Further, it defines pressure as the force per unit area and discusses how liquid pressure increases with depth due to the weight of the liquid above. Archimedes' principle of upthrust or buoyancy is also summarized.
This document provides an introduction to work, energy and power. It defines work as the product of force and displacement in the direction of force. Positive work is when force and displacement are in the same direction, while negative work is when they are in opposite directions. Kinetic energy is defined as half the mass times the velocity squared. The work-energy theorem states that work done equals the change in kinetic energy. Potential energy is the energy an object has due to its position or state. The conservation of mechanical energy principle applies to systems where only conservative forces act. It states the total mechanical energy of the system, which is the sum of kinetic and potential energy, remains constant. An example is provided of calculating work and energy for a
This document discusses key concepts relating to forces in physics. It defines a force as a push or pull and notes they can be measured in newtons. Balanced forces cause no acceleration while unbalanced forces produce changes in motion. Friction and air resistance are examples of contact forces. Hooke's law states the extension of a spring is proportional to the applied load. Newton's second law relates force, mass and acceleration using the equation F=ma.
This document discusses key concepts relating to forces in physics. It defines a force as a push or pull and notes they can be measured in newtons. Balanced forces will not cause a change in motion, while unbalanced forces will. Friction and air resistance are examples of contact forces. Hooke's law states the extension of a spring is proportional to the applied force. Newton's second law relates force, mass and acceleration using the equation F=ma.
Sehs 4.3โ biomechanics ii (4.3.3, force, com)strowe
ย
The document discusses the fundamentals of biomechanics, including forces and levers. It defines a force as a push or pull that acts on an object, and can be quantified by both magnitude and direction. Forces can be contact forces, which require touching the object, or long-range forces like gravity that act without contact. Levers are rigid bars that rotate around a fulcrum, and there are three classes of levers that differ based on the relative positions of the fulcrum, effort, and resistance. The center of mass of an object can change based on factors like body position, external loads, and age or sex, and affects an object's stability.
This document contains information about an introductory fluid mechanics course, including:
- The lecturer's name and contact information, as well as consultation hours for the lecturer and another professor.
- An outline of topics to be covered, including fluid motion, thermal physics, electricity, and revision.
- A brief overview of fluid properties like density, pressure, compressibility of gases, liquids and solids.
- Explanations of concepts like hydrostatic equilibrium, Pascal's law, Archimedes' principle, buoyancy, and the continuity equation.
- Examples of calculating pressure, buoyant force, and applying conservation of mass.
The bottles did not move because of inertia - their mass resists changes in motion. It is a real demonstration of inertia. To pull it off:
- The bottles are glued to the table, so they cannot slide when pushed.
- The person pushes on the table, not directly on the bottles, so the bottles feel less force than what appears.
- Quick camera cuts and angles are used to hide that the bottles are fixed in place. It's an illusion that fools the eye through clever filming.
So in summary, it uses inertia and camera tricks to create the illusion that the bottles are resisting the push through their own inertia alone.
This document defines force and gravity. It explains that force is a push or pull that can cause an object to change its motion or speed. There are different types of forces including contact forces like friction and non-contact forces like magnetic and gravitational forces. Gravity is the force of attraction between all objects with mass and the Earth. The center of gravity is the point where all of an object's weight can be considered to be concentrated. An object's stability depends on whether its line of gravity falls within the base of support.
This document provides definitions and explanations of basic biomechanical concepts including:
- Mass is the quantity of matter an object contains and is measured in kilograms. Weight is the force exerted on a surface due to gravity and is measured in kilograms-force.
- A force can produce movement or deformation and is measured in Newtons. Newton's laws of motion describe how objects interact under various forces.
- The centre of gravity is the point where total mass of an object is considered to be concentrated. An object's stability depends on the position of its centre of gravity relative to its base of support.
- Forces can be analyzed using graphical methods like the parallelogram and triangle methods
This document provides an overview of kinetics, including definitions of force, methods of calculating force, types of forces, force vectors, naming conventions for forces, and concepts related to force including gravity, equilibrium, and force systems. Specifically, it defines force as that which produces or modifies motion, discusses Newtons as a unit of force, and covers the two types of forces - external and internal. It also addresses centre of gravity, line of gravity, base of support, and their relationship to stability. The three types of equilibrium - stable, unstable, and neutral - are defined. Finally, it outlines the four types of force systems: linear, parallel, rotational, and concurrent.
Here are the steps to re-arrange the surfaces by slipperiness:
1. Ice
2. Wet Mud
3. Wet Grass
4. Thick Carpet
5. Wet concrete
6. Dry concrete
2. a. An ice skater performing a routine wants as little friction as possible.
b. A driver driving a car on a wet road wants as much friction as possible.
c. A mountain biker riding down a steep muddy hill wants as little friction as possible.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
ย
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the bodyโs response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
This presentation was provided by Rebecca Benner, Ph.D., of the American Society of Anesthesiologists, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
ย
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...EduSkills OECD
ย
Andreas Schleicher, Director of Education and Skills at the OECD presents at the launch of PISA 2022 Volume III - Creative Minds, Creative Schools on 18 June 2024.
2. RECAP (FORCES)
FORCE Is defined based on what it can cause bodies to do, it may cause a
bodyโs length to increase or decrease. IT CAN CAUSE A BODYโS REST
POSITION TO CHANGE OR IF IN MOTION TO CHANGE IT DIRECTION
hence
FORCE is defined as a push or a pull that can change a bodies
state of rest or uniform motion in a straight line.
3. TYPES OF FORCES
โขTHERE ARE TWO TYPES OF FORCES. THESE ARE
๏ถCONTACT FORCE / LOCAL FORCE
๏ถNON โ CONTACT / NON โ LOCAL / FORCE FIELDS
4. CONTACT FORCE
โขThey are forces that are experienced by bodies when they
are in direct contact with the source of the force.
โขEXAMPLES
๏ฑUpthrust
๏ฑFrictional force
๏ฑTension force
๏ฑSurface tension
๏ฑForces exerted on a ball when kicked
๏ฑViscous force (fluid resistance)
5. NON โCONTACT FORCE
โขThey are forces that are experienced by bodies that may or
may not be in direct contact with the source of the force.
โขEXAMPLES
๏ฑMagnetic force
๏ฑGravitational force
๏ฑElectric Force
๏ฑNuclear force
NB: CONTACT FORCE ARE CALLED LOCAL FORCE BECAUSE THE SOURCE OF THE FORCE MUST BE IN THE
AREA(LOCALITY) OF THE OBJECT.
6. FRICTIONAL FORCEโขIt is the tangential force that acts on surfaces in contact and which opposes
their relative motion. It is experienced by solid bodies in contact.
โขUSES / ADVANTAGES OF FRICTIONAL FORCES
๏It makes body in motion to stop
๏It is use for sharpening cutlasses
๏It makes walking possible
๏It enables us light fire
๏It makes writing possible
๏It enables a screw or a nail to remain in place after being screwed into
position.
7. โขDISADVANTAGES OF FRICTIONAL
๏ It makes the sole of shoes wear and tear
๏It produces heat when 2 solid bodies in contact makes relative motion
๏It reduces the efficiency of a machine
โขHOW WE WILL REDUCE FRICTION
๏ Greasing solid surfaces in contact
๏Introducing impurities between surfaces reduces friction
๏By introducing spherical metallic balls in between two metals moving
over each other has in ball bearings or race reduces friction.
8. BALL RACE OR BEARING & LABELLING
Spherical body
Metal run
Metal
9. TWO TYPES OF FRICTION
โขTHESE ARE:
1) STATIC โ These opposes motion of bodies when they are stationary
2) DYNAMIC - These opposes motion of bodies already in motion
Static friction is always bigger than they the dynamic frictional force
10. NORMAL FORCE OR REACTION
It is the component of a supported force that is perpendicular to
the supporting surface.
HORIZONTAL SURFACE
11. โขEXAMPLES
Determine the reaction exerted on a surface when a 20 kg body
is placed on the surface. Assume horizontal.
SOLUTION
Reaction = ๐ ร ๐
= 20 ร 10
= 200 ๐
13. โขEXAMPLES
A 10 kg mass rest on a surface at 10ยฐ to the horizontal. Calculate
i. The force that presses the body unto the plane
ii. The force that tries to pull the body down along the surface
iii. The reaction
14. 1) ๐๐๐๐๐ ๐ = 10 ร 10 cos 10 = 98.48 ๐
2) ๐๐๐ ๐๐ ๐ = 10 ร 10 sin 10 = 17.36 ๐
3) ๐ = ๐๐๐๐๐ ๐ = 10 ร 10 cos 10 = 98.48 ๐
LIMITING STATIC FRICTION
This is the minimum force required to move a body at rest. The
force is described as dynamic limiting frictional force when it is
the minimum force that must be applied on a moving body to make
the body move at a constant velocity.
15. โขCoefficient of Static Friction
It is defined as the
๐ฅ๐ข๐ฆ๐ข๐ญ๐ข๐ง๐ ๐ฌ๐ญ๐๐ญ๐ข๐ ๐๐ซ๐ข๐๐ญ๐ข๐จ๐ง๐๐ฅ ๐๐จ๐ซ๐๐
The normal force or reaction
.
๐ =
๐น๐ฅ
๐
or ๐น๐ฅ = ๐ ร ๐
Example
A 15 kg body is on a horizontal surface which has a coefficient of
friction of 0.25. Calculate
i) The normal force
ii) The limiting static frictional force
16. โข Solution
i. The normal force = ๐ ร ๐ = 15 ร 10 = 150 ๐
ii. The limiting static frictional force = ๐น๐ฅ = ๐๐ = 0.25 ร 150 = 37.5 ๐
EXAMPLE
A 100 kg body is on a plane inclined 30 ยฐ to the horizontal, if the frictional force on
the body is 50.0 N, calculate the
i. The normal force
ii. The coefficient of friction
17. โขSolution
i. The normal force = ๐๐๐๐๐ ๐ = 100 ร 10 cos 30 = 866.03 ๐
ii. The coefficient of friction ๐ =
๐น๐ฅ
๐
=
50 ๐
866.03
= 0.058 ๐
RESULTANT FORCE โ This is the difference between the total force in the
direction of motion and the total force opposite the direction of motion
๐น ๐ =Total force in the direction of motion โ total force opposite the direction
of motion
Or it can also be determined by mass ร acceleration = ๐ ร ๐ = ๐๐
18. EXAMPLE
A 20 kg body on a horizontal surfaces is pulled to the right with a force of
100N. Determine.
i. The frictional force
ii. The resultant force
iii. The acceleration ๐๐๐๐ ๐ = 0.2
19. โข SOLUTION
โข I. Frictional force , ๐น๐ฅ = ๐ ร ๐ , ๐ = ๐๐ = 20 ร 10 = 200 ๐
๐น๐ฅ = 0.2 ร 200 = 40.0 ๐
II. Resultant force , ๐ ๐ =Total force in the direction of motion โ total force opposite the
direction of motion = 100 โ 40 = ๐๐ ๐ต
20. III. Acceleration
๐น ๐ = ๐๐๐๐ ร ๐๐๐๐๐๐๐๐๐๐๐๐
60 = 20 ร ๐
โด ๐ =
60
20
= ๐ ๐๐โ๐
Home work 1
A 100 kg toy car is pulled up a plane inclined 30 ยฐ to the horizontal with a force of
1000 N. Given that the ๐น๐ฅ coefficient of the force is 0.25,
Calculate
i. ๐น๐ฅ force ii. Total force down along the plane iii. The resultant force
iii. The acceleration of the body act along the plane
23. Question
A 200 kg body rest on a surface inclined 25 ยฐ to the horizontal. If this body
is pulled down along the plane with a force of 100 N. Calculate
i. ๐น๐ฅ force ii. Total force in the direction of motion iii. The
resultant force iii. The acceleration of the body act along the plane
[Take ๐ ๐๐ 0.3]
24.
25. โข SOLUTION
i. FRICTIONAL FORCE, ๐น๐ฅ = 0.3 ร ๐ , ๐ = ๐๐๐๐๐ ๐
๐น๐ฅ = ๐ ร ๐๐๐๐๐ ๐ = 0.3 ร 2000 COS 25 = ๐๐๐. ๐๐๐ต
ii. TOTAL FORCE IN THE DIRECTION OF MOTION= ๐๐๐ ๐๐ ๐ + ๐น๐ = 200 ร 10 ๐ ๐๐25 + 100
= ๐๐๐. ๐๐ ๐ต
iii. RESULTANT FORCE, ๐ ๐ = ๐ก๐๐ก๐๐ ๐๐๐๐๐ ๐๐ ๐กโ๐ ๐๐๐๐๐๐ก๐๐๐ ๐๐ ๐กโ๐ ๐๐๐ก๐๐๐ โ
๐ก๐๐ก๐๐ ๐๐๐๐๐ ๐๐๐๐๐ ๐๐ก๐ ๐กโ๐ ๐๐๐๐๐๐ก๐๐๐ ๐๐ ๐๐๐ก๐๐๐ = 945. 24 โ 543.78 = ๐๐๐. ๐๐๐ต
iv. ACCELERATION =
๐ ๐๐ ๐ข๐๐ก๐๐๐ก ๐๐๐๐๐
๐๐๐ ๐
=
401.46
200
= ๐. ๐๐๐ ๐๐โ๐
26. MEASUREMENT OF COEFFICIENT OF ๐น๐ฅ
The test body is placed on a horizontal table that has a pulley fixed to one end of a thread that
is passing over a pulley attached to a scale pan. Masses are gently placed on the scale pan
until the test body just begins to move.
Weigh the mass on the scale pan and record it as ๐๐ . WEIGH THE TEST BODY AND RECORD THE MASS
AS ๐
THEORY
WHEN THE BODY JUST BEGINS TO MOVE ๐๐ ๐ = ๐
BUT ๐ = ๐๐ HENCE ๐น๐ฅ = ๐ ๐ ๐ REACTION ๐ = ๐๐
โด COEFFICIENT OF FRICTION ๐ =
๐น๐ฅ
๐
=
๐๐ ๐
๐๐
=
๐๐
๐
27.
28. TO DETERMINE ๐ USING INCLINED PLANE
โข The test body is placed on a plain. One end of the plane is gradually raised until the body
just begins to move.
โข The angle of inclination ๐ at this instant is measured with a protector. ๐ = ๐ญ๐๐ง ๐
29. When a body just begins to move ๐น๐ฅ =
๐๐ sin ๐
But ๐น๐ฅ = ๐๐
๐ = ๐๐๐๐๐ ๐
๐๐๐๐๐๐ ๐ = ๐๐๐ ๐๐ ๐
๐ =
๐๐๐ ๐๐ ๐
๐๐๐๐๐ ๐
=
sin ๐
cos ๐
= ๐ญ๐๐ง ๐ฝ
30. ARCHIMEDES PRINCIPLE
โข A body in a fluid apart from experiencing its own weight also experiences a vertically
directed upward force that tends to reduce the weight of the body.
โข Hence, bodies in fluid weigh less. UPTHRUST OR BUOYANT FORCE is the vertically directed
force experienced by bodies in fluid.
โข The volume of fluid displaced = the volume of the part of solid or body immerse in
fluid
โข The weight of the fluid displaced = the volume of solid immersed ร density of fluid ร
gravity
โข The weight of fluid displaced = UPTHRUST.
โข The apparent loss in weight of bodies is the UPTHRUST
31. QUESTIONS
โข A piece of wood has a mass of 200 g. When placed in ๐ป2 ๐ with 50 ๐๐3 of the wood in
๐ป2 ๐ , there is a loss in mass. Calculate
โข Volume of ๐ป2 ๐ displaced
โข Mass of ๐ป2 ๐ displaced
โข The upthrust on the wood
โข Find the apparent loss in mass of the wood.
32. SOLUTION
1. Volume of ๐ป2 ๐ displaced = 50 ๐๐3
2. Mass of ๐ป2 ๐ displaced = Density ร Vol. of the ๐ป2 ๐ = 1 ร 50 = 50 g
3. The upthrust on the wood =
50
1000
= 0.050 ร 10 ๐/๐ = 0.5 ๐
4. Apparent loss in mass of the wood = Mass in air โ mass in fluid = 200 โ 50 = 150 ๐
33. A 20 ๐๐3
balloon is left in air of density 0.0014 ๐/๐๐3
. Calculate the mass of air displaced and hence, the
upthrust.
Answer
Density =
๐๐๐ ๐
๐๐๐๐ข๐๐
Mass = Density ร Volume = 0.0014 ร 20 = 0.028 g
Upthrust =
0.028๐
1000
= 0.000028 ร 10 = ๐. ๐๐๐๐๐ ๐ต
Archimedes Principle
When a body is fully or partially immersed in a fluid, it experiences an upthrust equal to the weight of fluid
displaced.
NB: The upthrust reduces the weight.
34. FLOATATION
โขLaw of Floatation
A floating body displaces its own weight of fluid in the fluid in which its floates.
During Floatation
โข The volume of fluid displaced = the volume of the body immersed.
โข Mass of fluid displaced = Mass of the body
โข Upthrust = weight of body
35.
36. METHOD
โข 1. Fill an overflow can with ๐ป2 ๐ upto the spout level
โข 2. Weigh an empty beaker with an electric balance to record the mass ๐1
โข 3. Place the beaker below the spout
โข 4. Place the test tube in the ๐ป2 ๐ and add lead shots to the tube for the tube to float upright.
โข 5. Weight the beaker with the overflow ๐ป2 ๐ and record the mass ๐2
โข 6. Evaluate the mass of the overflow ๐ป2 ๐ AS ๐ = ๐2 โ ๐1
โข 7. Remove the test tube with the leadshots from the ๐ป2 ๐, weigh and record the mass as ๐
37. OBSERVATION AND CONCLUSION
โข It is found that ๐ = ๐๐ indicating that mass of the test tube/ body is equal to the mass of
overflow water
โข Weight of body = ๐๐
โข Upthrust = mass of fluid ร g = ๐ดโ ๐ ๐๐๐ข๐๐ ๐
โข ๐ด = ๐ถ๐๐๐ ๐ ๐ ๐๐๐ก๐๐๐๐๐ ๐๐๐๐, โ = โ๐๐๐โ๐ก , ๐ = ๐๐๐๐ ๐๐ก๐ฆ ๐ดโ = ๐๐๐๐ข๐๐
๐๐ = ๐ดโ๐๐
๐ = ๐ดโ๐(๐๐๐๐ ๐๐ก๐ฆ)
๐ = ๐๐
38. QUESTIONS
โข A test tube has a mass of 15 g, a cross sectional area of 1.5 ๐๐2
. The test tube floats
in the liquid of ๐ = 0.8 ๐/๐๐3. Calculate the depth of immersion of the test tube.
SOLUTION
๐ = 15 ๐ ๐ด = 1.5 ๐๐2 ๐ = 0.8 ๐/๐๐3
๐ = ๐ดโ๐
15 = 1.5 ร โ ร 0.8
โ =
15
1.2
= 12.5 ๐๐
39. QUESTION
โข A piece of wood floats in a liquid of relative density(RD) = 1.02 if the mass of the
wood is 25 kg and the volume of wood above the liquid is 0.0071 ๐3. Calculate the
total volume of the wood
SOLUTION
41. QUESTIONS
โข A 200g wood float in ๐ป2 ๐. If the top part of the wood is just above covered water. What
is the size length of the wood
SOLUTION
๐ = ๐๐
200 = ๐ ร 1
๐ = 200 ๐๐3
But ๐ฟ3 = ๐
๐ฟ3 = 200
๐ฟ = 5.85 ๐๐
42. HYDROMETER
โข This is an instrument used to measure relative density or consist off a uniform glass tube
containing lead shots. In another form of the instrument a uniform stem is mounted on a
large bulb that has lead shots in it as shown in the diagram below
44. WEIGHTLESSNESS โ MOTION IN A LIFT
When a lift accelerates downwards occupants feel lighter, however they feel heavier
when it accelerates upwards. These changes can be explained by considering the
resultant force, which acts on the occupants as a combination of two forces that are
acting. These are:
i. Force of gravity on weight
ii. The force needed to accelerate or decelerate the lift
45. WEIGHTLESSNESS โ MOTION IN A LIFT
If the lift accelerates downwards with an acceleration of ๐msโ2
then ๐พ = ๐๐ โ ๐๐. If
the lift accelerates upwards with acceleration of ๐msโ2
then ๐พ = ๐๐ + ๐๐ which
implies that the weight appears to be increased and occupants appear to be decreased.
As the lift increases its downwards acceleration, the apparent weight will be less and
less until eventually becomes zero. If the acceleration of the lift increases beyond 10
๐/๐ 2 then the person inside will fly. Spacemen experience weightlessness when the
acceleration of their spacecraft is greater than or equal to acceleration due to
gravity.
46. QUESTION
โข Calculate the force with which the feet of a passenger passes downwards on the floor of an
elevator accelerating upwards of 4 ร 10โ3
๐๐ โ2
if the passengerโs weight is 60 ๐.
SOLUTION
Weight of passenger = 60 N
But weight of passenger = ๐ฆ๐๐ฌ๐ฌ ๐จ๐ ๐ฆ๐๐ง ร ๐๐๐๐๐ฅ๐๐ซ๐๐ญ๐ข๐จ๐ง ๐๐ฎ๐ ๐ญ๐จ ๐ ๐ซ๐๐ฏ๐ข๐ญ๐ฒ
Mass of passenger =
๐ฐ๐๐ข๐ ๐ก๐ญ ๐จ๐ ๐ฉ๐๐ฌ๐ฌ๐๐ง๐ ๐๐ซ
๐๐๐๐๐ฅ๐๐ซ๐๐ญ๐ข๐จ๐ง ๐๐ฎ๐ ๐ญ๐จ ๐ ๐ซ๐๐ฏ๐ข๐ญ๐ฒ
I.E ๐ =
๐พ
๐
=
๐๐
๐๐
= ๐ ๐๐.
Let ๐๐ be the apparent weight of the passenger
โ ๐๐ = ๐๐ + ๐๐
โ ๐๐ = 6 ร 10 + 6 ร (4 ร 10โ3
)
โ ๐๐ = ๐๐. ๐๐๐ ๐
47. QUESTION
โข A man of mass 70 kg is standing in a lift. What force does the floor of the lift exert on the man if
the lift is
i. moving with a uniform velocity?
ii. accelerating at 3 ๐๐ โ2 upwards?
iii. Accelerating at 3 ๐๐ โ2
downwards? (Take ๐ = 10 ๐๐ โ2
)
48. SOLUTION
R is the normal reaction from the floor on the man
i)
Since the lift is moving with a uniform velocity, the resultant force is zero: ๐ = ๐๐ = 70 ร 10 =
700 ๐
R
mg
a
Since the lift is accelerating upwards
Equation of motion: ๐ โ ๐๐ = ๐๐
โ ๐ = ๐๐ + ๐๐ = ๐ ๐ + ๐ = 70 10 + 3 = 70 ร 13 = ๐๐๐ ๐ต
49. ii)
Since the lift is accelerating downwards
Equation of motion: ๐๐ โ ๐ = ๐๐
โ ๐ = ๐๐ โ ๐๐ = ๐ ๐ โ ๐ = 70 10 โ 3 = 70 ร 7 = ๐๐๐ ๐ต
50. CONNECTED BODIES
Two particles connected by a light inextensible string passing over a fixed light smooth
frictionless pulley are called connected bodies. The tension in the string is the same
throughout its length so the body is acted upon by the same tension. Problems concerned
with connected bodies usually involve finding the acceleration of the system and the
tension in the string.
54. PULLEY SYSTEM
Because the direction ๐1 ๐ is greater than the ๐2
๐1 > ๐2
For ๐ ๐
๐1 ๐ = ๐1 ๐ โ ๐ โ (1)
For ๐ ๐
๐2 ๐ = ๐ โ ๐2 ๐ โ 2
Eqn (1) + eqn(2)
๐1 ๐ + ๐2 ๐ = ๐1 ๐ โ ๐2 ๐
๐ ๐1 + ๐2 = ๐1 ๐ โ ๐2 ๐
๐ =
๐ ๐ ๐
๐ ๐ + ๐ ๐
โ
๐ ๐ ๐
๐ ๐ + ๐ ๐
55. A thread is passed over a pulley. 10 kg mass and 8 kg mass are suspended at the ends of
the ropes. Draw the arrangement and indicate the body force diagram on the masses.
Evaluate
1. The acceleration of either masses
2. The tension in the tie
Solution
For ๐ ๐
10๐ = 100 โ ๐ โ (1)
For ๐ ๐
8๐ = ๐ โ 80 โ 2
Eqn (1) + eqn(2)
18๐ = 20
๐ =
20
18
=
10
9
= 1.11 ๐/๐ 2
Substitute a into eqn 1
๐ป = ๐๐. ๐ ๐ต