Question
A body of mass 5 kg initially at rest is subjected to a force of 20N. What is the kinetic energy acquired by the body at the end of 10 seconds?
Solution
Initial velocity of body, u = 0 m/s
Mass of body, m = 5 kg
Force on the body, F = 20N
Time for which force acts on body t = 10 sec.
Therefore,
Acceleration of body, a= 4m/s2
Now the displacement of body is,
Work done by force,
And this work is converted into K.E.
Hence kinetic energy = 4 KJ
