A ball of mass 0.2 ~kg is thrown vertically upwards by applying a force by hand. If the hand moves 0.2 ~m while applying the force and the ball goes upto 2 ~m height further, find the magnitude of the force. (Consider .g=10 ~m / s ² ) .

Step-by-step solution

Let the velocity of the ball just when it leaves the hand is u then applying, array l v²-u²=2 a for upward journey -u²=2(-10) 2 u²=40 array Again applying v²-u²=2 a s for the upward journey of the ball, when the ball is in the hands of the thrower, array l v²-u²=2 a s 40-0=2(a) 0.2 a=100 ~m / s ² F =m a=0.2 100=20 ~N N -m g=20 N =20+2=22 ~N array