Question

If a boy (m = 50kg) at rest on skates is pushed by another boy who exerts a force of 200 N on him and if the first boy's final velocity is 8 m/s, what was the contact time? t= s

Answer 1

Answer:

t = 2 seconds

Explanation:

It is given that,

Mass of a boy, m = 50 kg

Initial speed of boy, u = 0

Final speed of boy, v = 8 m/s

Force exerting by another boy, F = 200 N

Let t is the time of contact. The force acting on an object is given by :

F = ma

a is acceleration

So,

$F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{50\times 8}{200}\\\\t=2\ s$

So, the contact time is 2 seconds.