Online Test of Chapter 11 Work Energy and Power 1 Science| Class 9th

1. A body is acted upon by a force 25 N acquires of 2.5 ms^-2 and covers a distance of the force. If the body starts from rest, the Kinetic energy acquired by it is?​
(i) 75 J
(ii) 25 J
(iii) 250 J
(iv) 100 J

2. A freely falling body during its fall will have
(i) Kinetic energy
(ii) Potential energy
(iii) Sound energy
(iv) Both kinetic energy and potential energy

3. A boy climbs on to a wall that is 3.4 m high and gains 2250 J of potential energy. What is the mass of the boy? Take g = 9.8 m/sec²
(i) 70 kg
(ii) 50 kg
(iii) 67.5 kg
(iv) 62.5 kg

4. A body of mass 4 kg has a momentum of 25 kg m/s, its K.E. is:
(i) 70.66 J
(ii) 78.12 J
(iii) 100 J
(iv) 25.5 J

5. What happens to K.E. of a body when 3/4 th of mass is removed and its velocity is doubled?
(i) becomes 4 times
(ii) no change
(iii) becomes 1/2 times
(iv) becomes 1/4 times

6. Elastic potential energy of a body can be achieved by
(i) setting it into motion
(ii) raising the body to a height
(iii) using an elastic band to tie the body
(iv) compressing or stretching the body

7. If the velocity of a moving car is halved, its kinetic energy would
(i) Double
(ii) Become Half
(iii) Become one fourth
(iv) Remain same

8. A fish with weight 35 kg dives and hits the ground (zero height) with kinetic energy equal to 3500J. Find the height through which fish dived. Take g = 10 m/s²
(i) 1 km
(ii) 100 m
(iii) 10 m
(iv) 20 m

9. Which of the following is not an example of potential energy?
(i) A compressed spring
(ii) Water stored in the reservoir of dam
(iii) A stretched rubber band
(iv) A moving car

10. How fast should a person with mass 50kg walk so that his kinetic energy is 625 J ?
(i) 15 km/s
(ii) 0.5 m/s
(iii) 5 m/s
(iv) 5 Km/s