I taught physics at Texas State University (elementary and algebra-based). This is a slide show I put together quickly for a friend. I'll be ading more, mostly on classical physics.
Drawing Free Body Diagrams for Engineering Staticsanita74117
I taught elementary and engineering physics (algebra based) at Texas State University in San Marcos, Texas. I made this slide show really quick for a friend. I'll be adding more classical mechanics slideshows in the future.
Drawing Free Body Diagrams for Engineering Staticsanita74117
This is a quick slide show I put together for a friend. I'll have more to come. I taught elementary and engineering physics (algebra based) at Texas State University in San Marcos. Most of the slide shows I plan to do will be physics related
Drawing Free Body Diagrams for Engineering Staticsanita74117
This slide show is a work in progress. I am putting together a short introduction to drawing free body diagrams for physics and engineering problems. Hint - learn Newton's 3rd law first. It makes learning the other two a breeze. I'll be updating and adding slide shows soon.
Free-body diagrams represent objects and the forces acting on them as vectors. They are useful for analyzing equilibrium situations where the net force on an object equals zero. There are several types of forces that may act on an object including normal force, tension, friction, and weight. Normal force is perpendicular to the surface an object rests on, tension is a pulling force from a rope or string, and friction opposes motion between two surfaces in contact.
The document discusses key concepts in dynamics including different types of forces like normal force and friction. It explains Newton's laws of motion and how they can be applied to solve dynamics problems. Examples are provided on how to use the laws of motion to analyze inclined planes, lifts, tensions in connected objects, and other dynamics scenarios. Key concepts covered in 3 sentences or less include: Newton's laws of motion are introduced to explain how forces cause motion or changes in motion. Different types of forces like normal force, friction, and tension are defined. Examples are given on how to apply Newton's laws to solve dynamics problems involving inclined planes, connected objects, and lifts.
The document discusses Newton's laws of motion. It provides background on Aristotle and Galileo's views, introduces Newton and his three laws, and gives examples of each law in action. Key points include Newton's first law of inertia, his second law relating force, mass and acceleration, and examples of problems applying the second law.
The document discusses key concepts in mechanics including:
1. Free body diagrams show only the external forces acting on an object and are useful for solving dynamics problems.
2. Newton's Second Law states that acceleration is proportional to net force and inversely proportional to mass.
3. Impulse is the product of force and time and equals change in momentum, affecting how objects move after collisions or other impacts.
Drawing Free Body Diagrams for Engineering Staticsanita74117
I taught elementary and engineering physics (algebra based) at Texas State University in San Marcos, Texas. I made this slide show really quick for a friend. I'll be adding more classical mechanics slideshows in the future.
Drawing Free Body Diagrams for Engineering Staticsanita74117
This is a quick slide show I put together for a friend. I'll have more to come. I taught elementary and engineering physics (algebra based) at Texas State University in San Marcos. Most of the slide shows I plan to do will be physics related
Drawing Free Body Diagrams for Engineering Staticsanita74117
This slide show is a work in progress. I am putting together a short introduction to drawing free body diagrams for physics and engineering problems. Hint - learn Newton's 3rd law first. It makes learning the other two a breeze. I'll be updating and adding slide shows soon.
Free-body diagrams represent objects and the forces acting on them as vectors. They are useful for analyzing equilibrium situations where the net force on an object equals zero. There are several types of forces that may act on an object including normal force, tension, friction, and weight. Normal force is perpendicular to the surface an object rests on, tension is a pulling force from a rope or string, and friction opposes motion between two surfaces in contact.
The document discusses key concepts in dynamics including different types of forces like normal force and friction. It explains Newton's laws of motion and how they can be applied to solve dynamics problems. Examples are provided on how to use the laws of motion to analyze inclined planes, lifts, tensions in connected objects, and other dynamics scenarios. Key concepts covered in 3 sentences or less include: Newton's laws of motion are introduced to explain how forces cause motion or changes in motion. Different types of forces like normal force, friction, and tension are defined. Examples are given on how to apply Newton's laws to solve dynamics problems involving inclined planes, connected objects, and lifts.
The document discusses Newton's laws of motion. It provides background on Aristotle and Galileo's views, introduces Newton and his three laws, and gives examples of each law in action. Key points include Newton's first law of inertia, his second law relating force, mass and acceleration, and examples of problems applying the second law.
The document discusses key concepts in mechanics including:
1. Free body diagrams show only the external forces acting on an object and are useful for solving dynamics problems.
2. Newton's Second Law states that acceleration is proportional to net force and inversely proportional to mass.
3. Impulse is the product of force and time and equals change in momentum, affecting how objects move after collisions or other impacts.
1) Inertia is the tendency of an object to resist changes in its motion. Mass is a measure of an object's inertia, with more massive objects being harder to accelerate or decelerate.
2) Newton's second law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This relationship can be expressed as F=ma.
3) Newton's third law states that for every action force there is an equal and opposite reaction force. Forces always occur in action-reaction pairs between interacting objects.
Newton's three laws of motion are summarized as follows:
1. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2. The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
3. For every action, there is an equal and opposite reaction.
Newton's three laws of motion are summarized as follows:
1) An object at rest stays at rest and an object in motion stays in motion unless acted upon by an unbalanced force.
2) The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
3) For every action, there is an equal and opposite reaction.
Newton's three laws of motion are summarized as follows:
1) Newton's First Law states that objects at rest will stay at rest and objects in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2) Newton's Second Law establishes the relationship between an object's mass, its acceleration, and the applied force as F=ma.
3) Newton's Third Law describes that for every action force there is an equal and opposite reaction force.
Newton's three laws of motion are summarized as follows:
1) Newton's First Law states that objects at rest will stay at rest and objects in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2) Newton's Second Law establishes the relationship between an object's mass, its acceleration, and the applied force as F=ma.
3) Newton's Third Law describes that for every action force there is an equal and opposite reaction force.
Newton's three laws of motion are summarized as follows:
1) An object at rest stays at rest and an object in motion stays in motion unless acted upon by an unbalanced force.
2) The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
3) For every action, there is an equal and opposite reaction.
1) Three boxes with masses m1 = 45 kg, m2 = 22 kg, and m3 = 33 kg are resting on a horizontal surface without friction. A horizontal force F of 50 N pushes the boxes to the right.
2) Applying Newton's Second Law to each box yields an acceleration of 0.5 m/s^2 for all boxes.
3) The force exerted by m2 on m3 is 27.5 N, and the force exerted by m1 on m2 is also 27.5 N.
- A force is a push or pull on an object due to its interaction with other objects. Common forces include gravity, normal force, tension, friction, electromagnetic force, and contact force.
- Forces are represented by arrows, with the length proportional to the magnitude. Forces can be added vectorially to find the net/resultant force. If the net force is nonzero, the object will accelerate. If it's zero, the object will maintain a constant velocity or remain at rest.
- For every action there is an equal and opposite reaction. The forces due to interactions between two objects are always equal in magnitude and opposite in direction.
Newton's laws of motion describe the relationship between an object and the forces acting upon it, and its response to those forces. The three laws are:
1) An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2) The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the direction of the net force, and inversely proportional to the mass of the object.
3) For every action, there is an equal and opposite reaction.
The document provides explanations and examples of these laws, different types of forces including contact
This document discusses representation in physics, specifically focusing on free-body diagrams. It defines what a free-body diagram is and provides examples of drawing them to represent different forces like weight, tension, and contact forces. Key examples include a person standing, a hanging picture, and boats being towed. The document also discusses the effects of friction, like how it allows cars and feet to move forward, and the factors that influence the amount of friction between surfaces.
This document discusses the concept of forces in physics. It defines a force as a push or pull on an object and explains that forces are vectors that have both magnitude and direction. There are four main forces in nature: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force. Dynamics and statics are introduced as areas of study related to forces and motion. Newton's three laws of motion are outlined. Common ways of measuring mass and examples of force problems are provided, including free body diagrams, friction, inclined planes, and pulleys.
Newton's laws of motion by Mphiriseni Khwandamkhwanda
Newton's Laws of Motion document summarizes Newton's three laws of motion. It discusses Newton's first law, stating that objects at rest stay at rest and objects in motion stay in motion with constant velocity unless acted upon by an unbalanced force. It addresses misconceptions about the first law. Newton's second law states that acceleration is directly proportional to net force and inversely proportional to mass. Problems are provided applying the laws, including drawing free-body diagrams and solving equations of motion. Newton's third law is not discussed.
Physics Chapter 10 section 1 Work, Energy, and PowerIbrahim Mutawea
Work is done when a force causes an object to move through a displacement. Work can change the energy of a system based on the work-energy theorem, which states that work done on a system equals the change in its energy. Power is the rate at which work is done or energy is transferred, measured in watts. It is calculated by dividing work by time or by multiplying force, velocity, and the cosine of the angle between them.
Force is any interaction that, when unopposed, will change the motion of an object. There are two types of forces: contact forces that require direct physical contact between objects, and non-contact forces that act over a distance without direct contact. Gravity is the non-contact force that attracts any two masses. The document goes on to define weight as a force and explain the relationship between mass and weight. It also introduces Hooke's law, Newton's laws of motion, and the law of universal gravitation.
With this mantra success is sure to come your way. At APEX INSTITUTE we strive our best to realize the Alchemist's dream of turning 'base metal' into 'gold'.
The document discusses the difference between mass and weight. Mass is the amount of matter in an object and does not change in different gravitational fields, while weight is the gravitational force exerted on an object's mass and does change in different fields due to differing gravitational strengths. It provides examples of how much an object would weigh on different planets and celestial bodies due to their different gravitational pulls, noting weight is calculated by multiplying mass by the local gravitational field strength.
The forces acting on the box are:
1. Applied force (Fa) by the boy pulling the rope towards the right.
2. Frictional force (Ff) by the floor on the box opposing the motion towards the left.
3. Normal force (Fn) by the floor on the box perpendicular to the surface.
To determine the resultant force, we add the forces acting on the same line of action (towards the right and left).
Fa - Ff = Resultant force
Since Fa is greater than Ff, the resultant force is towards the right. Therefore, the box will accelerate towards the right direction as the net force is unbalanced to the right.
The document describes key concepts in physics including energy, force, motion, waves, electricity, and magnetism. Some key points covered include:
- Identifying energy transformations and transfers of heat energy through conduction, convection, and radiation.
- Describing and calculating concepts like velocity, acceleration, Newton's laws of motion, and mechanical advantage of simple machines.
- Investigating light and sound phenomena, static electricity, and the relationship between voltage, current and resistance in electric circuits.
- Relating electricity and magnetism and their common applications.
The document discusses concepts related to equilibrium in physics including:
- Equilibrium as a condition where net forces are balanced out
- Statics as the study of structures in equilibrium under static forces
- Conditions for translational and rotational equilibrium as the sum of forces and sum of torques being equal to zero respectively
- Examples of calculating tensions in ropes and finding the center of gravity to solve equilibrium problems
A force is any push or pull that can cause an object to change its motion. The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, as described by Newton's Second Law. Newton's Third Law states that for every action force there is an equal and opposite reaction force.
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
More Related Content
Similar to Drawing Free Body Diagrams for Engineering Statics
1) Inertia is the tendency of an object to resist changes in its motion. Mass is a measure of an object's inertia, with more massive objects being harder to accelerate or decelerate.
2) Newton's second law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This relationship can be expressed as F=ma.
3) Newton's third law states that for every action force there is an equal and opposite reaction force. Forces always occur in action-reaction pairs between interacting objects.
Newton's three laws of motion are summarized as follows:
1. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2. The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
3. For every action, there is an equal and opposite reaction.
Newton's three laws of motion are summarized as follows:
1) An object at rest stays at rest and an object in motion stays in motion unless acted upon by an unbalanced force.
2) The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
3) For every action, there is an equal and opposite reaction.
Newton's three laws of motion are summarized as follows:
1) Newton's First Law states that objects at rest will stay at rest and objects in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2) Newton's Second Law establishes the relationship between an object's mass, its acceleration, and the applied force as F=ma.
3) Newton's Third Law describes that for every action force there is an equal and opposite reaction force.
Newton's three laws of motion are summarized as follows:
1) Newton's First Law states that objects at rest will stay at rest and objects in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2) Newton's Second Law establishes the relationship between an object's mass, its acceleration, and the applied force as F=ma.
3) Newton's Third Law describes that for every action force there is an equal and opposite reaction force.
Newton's three laws of motion are summarized as follows:
1) An object at rest stays at rest and an object in motion stays in motion unless acted upon by an unbalanced force.
2) The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
3) For every action, there is an equal and opposite reaction.
1) Three boxes with masses m1 = 45 kg, m2 = 22 kg, and m3 = 33 kg are resting on a horizontal surface without friction. A horizontal force F of 50 N pushes the boxes to the right.
2) Applying Newton's Second Law to each box yields an acceleration of 0.5 m/s^2 for all boxes.
3) The force exerted by m2 on m3 is 27.5 N, and the force exerted by m1 on m2 is also 27.5 N.
- A force is a push or pull on an object due to its interaction with other objects. Common forces include gravity, normal force, tension, friction, electromagnetic force, and contact force.
- Forces are represented by arrows, with the length proportional to the magnitude. Forces can be added vectorially to find the net/resultant force. If the net force is nonzero, the object will accelerate. If it's zero, the object will maintain a constant velocity or remain at rest.
- For every action there is an equal and opposite reaction. The forces due to interactions between two objects are always equal in magnitude and opposite in direction.
Newton's laws of motion describe the relationship between an object and the forces acting upon it, and its response to those forces. The three laws are:
1) An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
2) The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the direction of the net force, and inversely proportional to the mass of the object.
3) For every action, there is an equal and opposite reaction.
The document provides explanations and examples of these laws, different types of forces including contact
This document discusses representation in physics, specifically focusing on free-body diagrams. It defines what a free-body diagram is and provides examples of drawing them to represent different forces like weight, tension, and contact forces. Key examples include a person standing, a hanging picture, and boats being towed. The document also discusses the effects of friction, like how it allows cars and feet to move forward, and the factors that influence the amount of friction between surfaces.
This document discusses the concept of forces in physics. It defines a force as a push or pull on an object and explains that forces are vectors that have both magnitude and direction. There are four main forces in nature: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force. Dynamics and statics are introduced as areas of study related to forces and motion. Newton's three laws of motion are outlined. Common ways of measuring mass and examples of force problems are provided, including free body diagrams, friction, inclined planes, and pulleys.
Newton's laws of motion by Mphiriseni Khwandamkhwanda
Newton's Laws of Motion document summarizes Newton's three laws of motion. It discusses Newton's first law, stating that objects at rest stay at rest and objects in motion stay in motion with constant velocity unless acted upon by an unbalanced force. It addresses misconceptions about the first law. Newton's second law states that acceleration is directly proportional to net force and inversely proportional to mass. Problems are provided applying the laws, including drawing free-body diagrams and solving equations of motion. Newton's third law is not discussed.
Physics Chapter 10 section 1 Work, Energy, and PowerIbrahim Mutawea
Work is done when a force causes an object to move through a displacement. Work can change the energy of a system based on the work-energy theorem, which states that work done on a system equals the change in its energy. Power is the rate at which work is done or energy is transferred, measured in watts. It is calculated by dividing work by time or by multiplying force, velocity, and the cosine of the angle between them.
Force is any interaction that, when unopposed, will change the motion of an object. There are two types of forces: contact forces that require direct physical contact between objects, and non-contact forces that act over a distance without direct contact. Gravity is the non-contact force that attracts any two masses. The document goes on to define weight as a force and explain the relationship between mass and weight. It also introduces Hooke's law, Newton's laws of motion, and the law of universal gravitation.
With this mantra success is sure to come your way. At APEX INSTITUTE we strive our best to realize the Alchemist's dream of turning 'base metal' into 'gold'.
The document discusses the difference between mass and weight. Mass is the amount of matter in an object and does not change in different gravitational fields, while weight is the gravitational force exerted on an object's mass and does change in different fields due to differing gravitational strengths. It provides examples of how much an object would weigh on different planets and celestial bodies due to their different gravitational pulls, noting weight is calculated by multiplying mass by the local gravitational field strength.
The forces acting on the box are:
1. Applied force (Fa) by the boy pulling the rope towards the right.
2. Frictional force (Ff) by the floor on the box opposing the motion towards the left.
3. Normal force (Fn) by the floor on the box perpendicular to the surface.
To determine the resultant force, we add the forces acting on the same line of action (towards the right and left).
Fa - Ff = Resultant force
Since Fa is greater than Ff, the resultant force is towards the right. Therefore, the box will accelerate towards the right direction as the net force is unbalanced to the right.
The document describes key concepts in physics including energy, force, motion, waves, electricity, and magnetism. Some key points covered include:
- Identifying energy transformations and transfers of heat energy through conduction, convection, and radiation.
- Describing and calculating concepts like velocity, acceleration, Newton's laws of motion, and mechanical advantage of simple machines.
- Investigating light and sound phenomena, static electricity, and the relationship between voltage, current and resistance in electric circuits.
- Relating electricity and magnetism and their common applications.
The document discusses concepts related to equilibrium in physics including:
- Equilibrium as a condition where net forces are balanced out
- Statics as the study of structures in equilibrium under static forces
- Conditions for translational and rotational equilibrium as the sum of forces and sum of torques being equal to zero respectively
- Examples of calculating tensions in ropes and finding the center of gravity to solve equilibrium problems
A force is any push or pull that can cause an object to change its motion. The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, as described by Newton's Second Law. Newton's Third Law states that for every action force there is an equal and opposite reaction force.
Similar to Drawing Free Body Diagrams for Engineering Statics (20)
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
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
2. NET FORCE
When the net force on an
object is zero, the
ACCELERATION of the object is
zero, However, the object may
still be moving IN A STRAIGHT
LINE
4. FUNDAMENTAL
FORCES
How many forces are involved
in a free body diagram?
1 Gravity
2 Electromagnetic
3 Strong Nuclear Force
4 Weak Nuclear Force
5. FUNDAMENTAL
FORCES
How many forces are involved
in a free body diagram?
1 Gravity
2 Electromagnetic
3 Strong Nuclear Force
4 Weak Nuclear Force
The strong and weak nuclear forces have very short
ranges and are only effective inside the nucleus.
Therefore, you only have TWO fundamental forces to
consider! Easy, right??
6. FUNDAMENTAL
FORCES
How many forces are involved
in a free body diagram?
1 Gravity
𝐹 = 𝐺
𝑚1𝑚2
𝑑2
In most cases, one of the two masses is the
earth (d is the radius of the earth, and Gm1/d2
is “little g” or approximately 9.8 m/s2).
Even placing an object at the top of a tall
skyscraper has little effect on gravity. The
acceleration due to gravity is usually a known
quantity given in the problem.
2 Electromagnetic
7. FUNDAMENTAL
FORCES
How many forces are involved
in a free body diagram?
1 Gravity
𝐹 = 𝐺
𝑚1𝑚2
𝑑2
2 Electromagnetic
Coulomb force
Magnetic force
Friction
Tension
Bouyant
Normal
Spring
Intermolecular
12. WHY IS THIS SO
HARD?
1.Resolve all force
vectors into their x y
and z components
2. Σ𝐹𝑛𝑒𝑡 = 0 𝑁
3.Draw each pair of
forces involved ONE
PAIR AT A TIME
Let’s make it simpler
13. Gravity
(assume the ropes have negligible weight. Then the force
of gravity on them is zero. You may exclude these two
pairs of forces)
Since we are only
concerned with the
forces acting on the
sign and not the
earth, we can
exclude the earth
and the reaction
force on it.
14. Gravity
(assume the ropes have negligible weight. Then
the force of gravity on them is zero. You may
exclude these two pairs of forces)
Intuitively, we might assume that the
force through each rope is 50N. But we
can also prove it mathematically.
𝑇1 = 𝑇2
𝑇1 + 𝑇2 = 100𝑁
A simple substitution gives us the
answer.
𝑇1 + 𝑇1 = 100𝑁
𝑇1 = 𝑇2 = 50𝑁
15. Gravity
(assume the ropes have negligible weight. Then the
force of gravity on them is zero. You may exclude
these two pairs of forces)
According to Newton’s 3rd Law of Gravity,
forces always occur in pairs.
• What object does the “reaction force”
act on?
• What is the magnitude and direction of
this “reaction force”?
16. If the only force acting on
the sign were the weight of
the sign, there would be a
NON-ZERO net force acting on
the sign, and it would
accelerate in the direction
of the net force (in this
case, towards the ground)
17. Tension
Fortunately, there are 2
ropes supporting the weight
of the sign.
The SUM of these forces that
are acting on the sign ADD
UP TO ZERO. We know this
because the sign is NOT
ACCELERATING
18. CHECK YOUR WORK
Did we include all
relevant forces?
Suggestion – always start
with gravity
So far, we have drawn the
diagram. In the next step, we
will calculate the horizontal
and vertical components of the
tension forces in each rope.
20. WHAT DO WE KNOW
𝑇1=𝑇2cosΘ
We know this because the acceleration
(and hence the net force) in the
horizontal direction is zero.
Don’t confuse these forces for
action/reaction pairs of forces!
Remember that the “reaction” forces
are acting on THE SIGN. An easy way
to remember this is to pretend the sign
were made of a stretchy material.
21. WHAT DO WE KNOW
In this problem, it is
ESSENTIAL to solve for
T2 before proceeding to
the horizontal forces.
Once you’ve done enough
of these problems,
you’ll see that each one
is a puzzle to be
solved.
𝑇1=𝑇2cosΘ