Work energy and power expression for work and definition

1. CHAPTER-5

2. What are you
doing my child ?
Don’t you see I am
doing my work.

3. Ha.. Ha…
Are you doing
work ?
Why are you laughing
..i am putting lot of force
to move you

4. I didn’t move even a
single step. Then how
can you say that you
are doing work?
What is he
saying ?

5. Pic 1 Pic 2

6. Pic
3

8. ❖ What are the pictures did you see ?
❖ Is there any force acting on these three situations?
❖ Can you say the source of applied force in “an
apple falling from the tree”?
❖ What about the source of applied force in second
picture?
❖ Who applied force in third picture?
❖ Is there any displacement takes place in above
pictures?

9. ❖ In which cases displacement is not happened?
❖ Which bodies undergo displacement in first and
second picture ?
❖ Is the force and displacement in same direction?
❖ Force are applied on bodies in all the above
situations but displacement does not takes place
isn’t it?
❖ Can we say that work is done in all the above
these pictures?

10. ❖ What are the situations in which work is done
and not done?
❖ Can you define work?
❖ How can we relate work displacement and force?

13. ❖ What do you observed in case 1?
❖ Is there any work done here?
❖ What is the reason?
❖ What do you observed in case 2?
❖ In which direction force is applied?
❖ In which direction displacement is takes place?
❖ Is there any work done here?
❖ What are the factors influence the work done?
❖ How can we relate work, force, displacement?

14. ❖ What is the unit of force and displacement?
❖ What is the unit of work?
❖ A force of 10N is applied continuously on a body.
If the body undergoes a displacement of 2m, find
out the magnitude of work done?

15. � F = 10N
� S = 2 m
� W = F * S
� = 10*2
� = 20 Nm
� = 20 J

17. ❖ WORK IS SAID TO BE DONE
ONLY WHEN A BODY
UNDERGOS DISPLACEMENT
IN THE DIRECTION OF
APPLIED FORCE
WORK

18. ❑ IF A FORCE OF F NEWTON IS
APPLIED COTINUOUSLY ON A
BODY AND THE BODY UNDERGOES
A DISPLACEMENT OF S METRE IN
THE DIRECTION OF THE FORCE,
THEN THE WORK DONE BY THE
APPLIED FORCE IS,
W= F.S

19. CHOOSE THE DISPLACEMENT
TAKES PLACE IN THE DIRECTION
OF FORCE AND NO
DISPLACEMENT FOR THE BODY IN
THE DIRECTION OF FORCE
APPLIED.

20. A car is pushed
by sitting inside
the car
A trolley is being pulled
Climbing
ladder with
load on head

21. FOLLOW UP
� Define work done?
�A force of 40 N applied on body and
its displacement in the direction of
force is 10m. Find work done?
�What is the unit of work?

22. � F=40N
� S=10m
� W=F*S
� =40*10
� = 400J

23. CREATE A CARTOON RELATING
THE WORK DONE.