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.

Question

Philoid · Accepted Answer

When the Velocity, v = 5 m/s

Mass, m = 20 kg

Then,

K.E. = mv²

= × 20 × (5) 2

= × 20 × 25

= 250 J

When the Velocity, v = 2 m/s

Mass, m = 20 kg

K.E. = mv²

= × 20 × (2) 2

= × 20 × 4

= 40 J

We know that,

Work done by force = Change in kinetic energy

= 250 - 40

= 210 J