Question

If a ball of mass 2 kg is moving with 20 m/s retarding force of 400 N acts on the ball find time taken to stop the ball​

Answer 1

Explanation:

F= m×a

=] F= m×{v-u}÷t

But since the ball stops then its final velocity will become 0

=] F= m×-20/t

=] -400= 2× 20/t. { We put -400 instead of putting 400 because the force is retarding the ball}

=] 1÷t = -400÷(2×-20}

=] 1÷t= 10

=] t= 1/10 seconds