`AB` is a platform of length `10 m` kept on frictionless horizontal surface. A man of same mass is standing on end `A`. Friction coefficient between shoe of the man and platform is `0.5`. Man starts running from `A` and stops at `B`. Find the minimum time (in seconds) required by the person to arrive at `B`.

Explanation

For minimum timer person should use maximum friction for speeding up half the time and slowing down with maximum fricition in next half time because he has finally to be stopped as stated in the question.