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=10m//s^2`).

Options

A. 20 N
B. 22 N
C. 4 N
D. 16 N

Answer

A

Explanation

Here the work done by hand hould be equal to change in potential energy of the ball
i.e., `W_("hand") = Delta U`
`rArr F_("hand") s = mgh`
`rArr F_("hand") = (mgh)/(s) = (0.2 xx 10 xx 2)/(0.2) = 20 N`.