Question

4. Certain force acting on a 20 kg mass changes its velocity from
5 m s-1 to 2 m s-1. Calculate the work done by the force.

Answer 1

Answer:

4. Certain force acting on 20 kg mass changes its velocity from 5 m s-1 to 2 m s-1. Calculate the work done by the force. (E k)2 = (1 )/2x 20 — (2)2 = 40 J

5. Kinetic energy is given by the expression, (E k) v = 1/2 mv^2

Where,

E k= Kinetic energy of the object moving with a velocity, v

(i) Kinetic energy when the object was moving with a velocity 5 m s-1

(E k)5 = 1/2 — 20 — (5)2 = 250 J

Kinetic energy when the object was moving with a velocity 2 m s-1

(E k)2 = (1 )/2x 20 — (2)2 = 40 J.

Answer 2

Answer:

$(E k)2 = (1 )/2x 20 — (2)2 = 40 J.$

Answer :-