Question

A force of 20 N acts on the ball for short duration. If ball of mass 0.5 kg acquire a speed of 4 m/s from the rest. For how long did this force act on the ball?

• A. 0.01 s
• B. 0.02 s
• C. 0.1 s
• D. 0.2 s
• E. 1 s

Answer 1

The correct option is C 0.1 s

Acceleration of the ball, $a=F/m=20/0.5=40m/s^2$

Using $v=u+at$ we get, $4=0+40t$ or $t=4/40=0.1s$