This is a summary of the topic "Energy, work and power" in the GCE O levels subject: Physics. Students taking either the combined science (chemistry/physics) or pure Physics will find this useful. These slides are prepared according to the learning outcomes required by the examinations board.
the relation between force and motion id described in Newtons three laws of motion. These laws are very simple statements and enable us to describe the future (or past) motion of body if we know the forces acting on it.
This is a summary of the topic "Energy, work and power" in the GCE O levels subject: Physics. Students taking either the combined science (chemistry/physics) or pure Physics will find this useful. These slides are prepared according to the learning outcomes required by the examinations board.
the relation between force and motion id described in Newtons three laws of motion. These laws are very simple statements and enable us to describe the future (or past) motion of body if we know the forces acting on it.
A simple ppt yet interactive on the topic work power and energy. With smooth design and looks the ppt is very good for clearing the basics related to this topic, hope it will help you further.
Physical Quantities--Units and Measurement--Conversion of UnitsKhanSaif2
This presentation covers physical quantities and their types, units and their types, conversion of units and order of magnitude in a very interactive manner. I hope this presentation will be helpful for teachers as well as students.
A simple ppt yet interactive on the topic work power and energy. With smooth design and looks the ppt is very good for clearing the basics related to this topic, hope it will help you further.
Physical Quantities--Units and Measurement--Conversion of UnitsKhanSaif2
This presentation covers physical quantities and their types, units and their types, conversion of units and order of magnitude in a very interactive manner. I hope this presentation will be helpful for teachers as well as students.
Appeal to All People: Help Stop Climate ChangeSlideShop.com
One of the serious environmental issues we are facing to day is climate change. What causes this? How do we help stop it? This presentation answers these questions.
More themed slides: https://slideshop.com/Themed-Slides/
CHAPTER 18
PLANAR KINETICS OF A RIGID BODY: WORK AND ENERGY (Sections 18.1-18.4)
Objectives:
a) Define the various ways a force and couple do work.
b) Apply the principle of work and energy to a rigid body.
APPLICATIONS
The work of the torque developed by the driving gears on the two motors on the mixer is transformed into the rotational kinetic energy of the mixing drum.
The work done by the compactor's engine is transformed into the translational kinetic energy of the frame and the translational and rotational kinetic energy of
its roller and wheels
2. Rotation: When a rigid body is rotating about a fixed axis passing through point O, the body has both translational and rotational kinetic energy:
T = 0.5m(vG)2 + 0.5IGw2
Since
vG = rGw, T = 0.5(IG + m(rG)2)w2 = 0.5IOw2
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'.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2. Why Energy?
Why do we need a concept of energy?
The energy approach to describing motion is
particularly useful when Newton’s Laws are
difficult or impossible to use
Energy is a scalar quantity. It does not have
a direction associated with it
3. What is Energy?
Energy is a property of the state of a system, not a
property of individual objects: we have to
broaden our view.
Some forms of energy:
Mechanical:
Kinetic energy (associated with motion, within system)
Potential energy (associated with position, within system)
Chemical
Electromagnetic
Nuclear
Energy is conserved. It can be transferred from
one object to another or change in form, but
cannot be created or destroyed
4. Kinetic Energy
Kinetic Energy is energy associated with the
state of motion of an object
For an object moving with a speed of v
KE
1 2
mv
2
SI unit: joule (J)
1 joule = 1 J = 1 kg m2/s2
5.
6. Work W
1 2 1
2
Fx x
Start with 2 mv 2 mv0
Work “W”
Work provides a link between force and energy
Work done on an object is transferred to/from
it
If W > 0, energy added: “transferred to the
object”
If W < 0, energy taken away: “transferred from
the object”
7. Work Unit
This gives no information about
the time it took for the displacement to occur
the velocity or acceleration of the object
Work is a scalar quantity
1 2 1
2
SI Unit
mv
mv0 ( F cos
2
2
Newton • meter = Joule
N • m = J
J = kg • m2 / s2 = ( kg • m / s2 ) • m
W
( F cos ) x
) x
8. Work: + or -?
Work can be positive, negative, or zero. The sign of
the work depends on the direction of the force
relative to the displacement
W
( F cos ) x
Work positive: W > 0 if 90°> > 0°
Work negative: W < 0 if 180°> > 90°
Work zero: W = 0 if = 90°
Work maximum if = 0°
Work minimum if = 180°
9. Example: When Work is Zero
A man carries a bucket of
water horizontally at constant
velocity.
The force does no work on the
bucket
Displacement is horizontal
Force is vertical
cos 90° = 0
W ( F cos ) x
10. Example: Work Can Be
Positive or Negative
Work is positive when
lifting the box
Work would be negative if
lowering the box
The force would still be
upward, but the
displacement would be
downward
11.
F
Work Done by a Constant Force
The work W done on a system
by an agent exerting a constant
force on the system is the
product of the magnitude F of
the force, the magnitude Δr of
the displacement of the point of
application of the force, and
cosθ, where θ is the angle
between the force and
displacement vectors:
W
F
r
F
r
r
II
I
0F
WI
WII
F r
F
r
r
F r cos
III
WIII
F r
IV
WIV
F r cos
February 11, 2014
12. Work Done by Multiple Forces
If more than one force acts on an object, then the
total work is equal to the algebraic sum of the work
done by the individual forces
Wnetnet
W
Wby by individual forces
Windividual forces
Remember work is a scalar, so
this is the algebraic sum
Wnet Wg WN WF
Wnet Wg WN WF
( F cos ) r
( F cos ) r
February 11, 2014
13. Work and Multiple Forces
Suppose µk = 0.200, How much work done on the
sled by friction, and the net work if θ = 30° and he
pulls the sled 5.0 m ?
( f k cos180 ) x
W fric
k
N x
k
fk x
(mg F sin ) x
(0.200)(50.0kg 9.8m / s 2
1.2 102 N sin 30 )(5.0m)
4.3 102 J
Wnet
WF W fric WN Wg
5.2 102 J
90.0 J
4.3 102 J
0 0
14. Kinetic Energy
object is the energy which it possesses due to
its motion.[1] It is defined as the work needed to accelerate
a body of a given mass from rest to its stated velocity.
Having gained this energy during its acceleration, the body
maintains this kinetic energy unless its speed changes. The
same amount of work is done by the body in decelerating
from its current speed to a state of rest.
In classical mechanics, the kinetic energy of a non-rotating
object of mass m traveling at a speed v is ½ mv².
In relativistic mechanics, this is only a good approximation
when v is much less than the speed of light.
15. Work-Kinetic Energy Theorem
Is the net work done on an object is
equal to the change in the kinetic
energy of the object.
Wnet = ∆KE
Net work is equal to kinetic energy
16. • Kinetic energy depends on speed and mass:
KE = ½mv2
Kinetic energy = ½ x mass x (speed)2
KE is a scalar quantity, SI unit (Joule)
17. • TRY TO SOLVE: Ex. A 7.00 kg bowling ball
moves at 3.00 m/s. how much kinetic
energy does the bowling ball have? how
fast must a 2.24 g table-tennis ball move in
order to have the same kinetic energy as
the bowling ball? Is the speed reasonable
for a table-tennis ball?
Given:
the subscript b and t indicate the
bowling ball and the table-tennis ball,
respectively.
Mb = 7.00 kg Mt = 2.24g Vb = 3.00m/s
Unknown: KEb = ? Vt = ?
18. Work-Kinetic Energy Theorem
When work is done by a net force on an
object and the only change in the object is its
speed, the work done is equal to the change
in the object’s kinetic energy
Speed will increase if work is positive
Speed will decrease if work is negative
Wnet
1
mv 2
2
1
2
mv0
2
19. Work-Energy Theorem
W= KE
W=KEf-KEi
“In the case in which work is done on a system
and the only change in the system is in its
speed, the work done by the net force equals
the change in kinetic energy of the system.”
20. • The Work-Kinetic Energy Theorem
can be applied to non isolated
systems
• A non isolated system is one that is
influenced by its environment
(external forces act on the system)
21. Work and Kinetic Energy
The driver of a 1.00 103 kg car traveling on the interstate at
35.0 m/s slam on his brakes to avoid hitting a second vehicle in
front of him, which had come to rest because of congestion
ahead. After the breaks are applied, a constant friction force of
8.00 103 N acts on the car. Ignore air resistance. (a) At what
minimum distance should the brakes be applied to avoid a
collision with the other vehicle? (b) If the distance between the
vehicles is initially only 30.0 m, at what speed would the
collisions occur?
22. Work and Kinetic Energy
3
v 0 35/,s m s m 1. m. 10 10 kg3 f 8 f k8 10 310 10 3
v
8 N
v0 0 35 .00.mms.0, v /0,,0, m 0,00001.00 3 ,10k, kg, .00 .00.00 3 N N
kg f k
35 / v
1
(a) We know v
Find the minimum necessary stopping distance
1 2 1 2
Wnet W fric Wg WN W fric
mv
mv
1 22 f 2 i
f k x 0 1 mv0
2
f k x 0 2 mv0
2
1
1 103 kg)(35.0m / s) 2
(8.00 108.N ) 103 N ) x (1.001.00 103 kg)(35.0m / s) 2
( 00 x
(
2
2
3
x 76.6.6m
x 76m
February 11, 2014
23. Work and Kinetic Energy
x
30 .0m, v0
35 .0m / s, m 1.00 10 3 kg, f k
(b) We know
Find the speed at impact.
Write down the work-energy theorem:
1 2
Wnet W fric
fk x
mv f
2
2
2
v 2 v0
fk x
f
m
v2
f
vf
1 2
mvi
2
2
(35 m / s) 2 (
)(8.00 10 3 N )(30 m)
1.00 10 3 kg
27.3m / s
8.00 10 3 N
745 m 2 / s 2