A man of mass `m` speeds up while running from rest to a speed v in a straight track along an inclined plane, after raising through a height `h`.
`W_(gravity)="work done by gravity on the man"`
`W_(friction)="work done by friction on the man"`
`W_(man)="work done by man"`
Which of the following options is correct regarding the various work done?

Options

A. (a) `W_(gravity)=-mgh`
B. (b) `W_(f riction)gt0`
C. (c) `W_(man)=mgh+1/2mv^2`
D. (d) `W_(f riction)=0`

Answer

A, C, D

Explanation

Work by friction will be zero if there is no slipping of the man's foot on incline. Work done by man will be equal to increase in his kinetic+potential energy.