The document discusses work, energy, and power. It defines key terms like work, force, kinetic energy, potential energy, and mechanical, heat, chemical, electrical, and nuclear energy. It provides examples of calculating work done and energy for objects in motion. The document also defines the unit of power as watts and provides examples of calculating power from scenarios involving work over time. It discusses different forms of energy like heat, internal, and nuclear energy and introduces the mass-energy equivalence relation E=mc2.

1. Work, Energy and Power
Monica G Sadhwani
ID No - 14162078

2. In this chapter you will come across
following terms
 Work
 Force
 Kinetic energy
 Potential Energy
 Mechanical energy
 Heat energy, chemical energy, Electrical
energy , Nuclear energy
 Power

3. Gist of Chapter
• What the chapter is about?

4. Let us start understanding what is
work??
 Work in Physics

5. Lets Test Our Brain
All the
Best

6. Instruction
 Just click on the answer you find correct
 Then you will be directed forward
 If you answer correctly you will move forward
 If your answer is wrong you will be directed towards concerned video or
file then make sure every time you go back and answer correctly and then
move forward
 Start here….

7. Q1.In case of negative work the angle between
the force and displacement is
(a) 00 °
(b) 450°
(c) 900 °
(d ) 180°

8. Watch the Video Again Attempt Again

9. Next Question

10. Q2. The work done on an object does not depend
upon the
(a) displacement
(b) force applied
(c) angle between force and displacement
(d) initial velocity of the object

11. Attempt Again

13. Q3. A body of mass 15 kg undergoes downward
displacement of 40 m under the effect of
gravitational force. Calculate work done (g = 10
m/s2
Acceleration a= g = 10 m/s2 , mass m = 15 kg
displacement s = 40 m
a)-6000 J
b) 6000 J
c) 600 J
d) 0 J

14. Attempt Again
Watch the Video
Again

15. Go Ahead

16. Q4. A body of mass 120 g is taken vertically
upwards to reach the height of 5m. Calculate
work done (g = 10 m/s2)
a) 6 J
b) 600 J
c) 0.6 J
d) - 6 J

17. Attempt Again

18. Next Question

19. Q5. Work done = Force x _______
a) distance
b) acceleration
c) velocity
d) speed

20. Next

21. Attempt Again
Watch the Video
Again

22. Q6. 1 joule = 1 _______
1. N m2
2. kg/m2
3. N m
4. N2 m2

23. Attempt Again

24. Move
Forward

25. Now Let Us Study about Energy
 Let us read something

26. Let Us Practice What we have
learnt about Energy…

27. Q7. A car is accelerated on a levelled road and
attains a velocity 4 times of its initial velocity. In
this process the potential energy of the car
(a) does not change
(b) becomes twice to that of initial
(c) becomes 4 times that of initial
(d) becomes 16 times that of initial

28. Lets
Read
Again
Now Try to
Answer

29. Next Question

30. Q8. Which one of the following is not the unit of
energy?
(a) joule
(b) newton metre
(c) kilowatt
(d) kilowatt hour

31. Lets
Read
Again

33. Q9. A body is falling from a height h. After it has
fallen a height h/2 , it will possess
(a) only potential energy
(b) only kinetic energy
(c) half potential and half kinetic energy
(d) more kinetic and less potential energy

34. Lets
Read
Again

36. Q10. When a body falls freely towards the earth,
then its total energy
(a) increases
(b) decreases
(c) remains constant
(d) first increases and then decreases

37. Lets
Read
Again

39. Q 11. Water stored in a dam possesses
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy

40. Lets
Read
Again

42. Q 12. When a spring is compressed its potential
energy …….
a) Remains constant
b) Reduces
c) Increases
d) Nothing can be said about it

43. Lets
Read
Again

45. Q 13. A body of mass 10 kg performs motion
along a circle of radius 5m with speed of 10
m/s. Work done during one revolution is ......
(A)2000 J
(B)1000 J
(C)500 J
(D) zero

46. Lets
Read
Again

48. POWER
Lets watch video

49. Q14. 1 kWh= ........... J
(A)36 X 106
(B)3.6 X 106
(C) 3.6 X 107
(D) 3.6 X l05

52. Q 15.A boy of mass 40 kg climbs a staircase of
30 steps, each of 0.2m height, in 30 s. Calculate
power (g = 9.8 m/s2)
a. 8 W
b. 80 W
c. 18 W
d. 9 W

55. Q 16. Engine of a car of mass 1500 kg, keeps car
moving with constant velocity 5m/s. If
frictional force is 1000 N, power of engine is
...............
(A)5 kW
(B) 7.5 kW
(C)15 kW
(D) 75 kW

58. Q 17.Height of water dam in hydroelectric power
station is 20 m. How much water, in 1 second,
should fall on turbine, so that 1MW power is
generated ? (g = 10m/s2)
(A)5000 kg
(B)10,000 kg
(C)500 kg
(D)7,500 kg

61. Different Forms of Energy

62. Q 18.The law of conservation of energy is a
statement that
A) energy must be conserved and you are
breaking a law if you waste energy.
B) the supply of energy is limited so we must
conserve.
C) the total amount of energy is constant.
D) energy cannot be used faster than it is
created.

65. Q 19. The kinetic energy associated with the
random motion of the constituent particles of a
body, is known as
a) Heat Energy
b) Internal Energy
c) Nuclear Energy
d) None of the above

68. Q 20.Mass and energy are mutually
convertible according to the following relation
a) M= EC2
b) E = mc2
c) E = 1/2mc2
d) None of the above