In-moving-a-body-of-mass-m-up-and-down-a-rough-incline-plane-of-inclination-work-done-is-S-is-length-of-the-planck-and-is-coefficient-of-friction-

Question Number 18581 by Tinkutara last updated on 25/Jul/17

In moving a body of mass m up and

down a rough incline plane of inclination

θ, work done is (S is length of the planck,

and μ is coefficient of friction) .

Answered by ajfour last updated on 25/Jul/17

W = 2 μ mgScos θ

Commented by Arnab Maiti last updated on 25/Jul/17

Force of friction = μ mgcos θ

Work done to take the body

up against force of friction is

= μ mgcos θ \times S

Again when it is taken to down

again work done against force

and friction = μ mgScos θ

So total work done against

force of friction, w_{1} = 2 μ mgScos θ

The work done against gravitational

force = 0, as final height = initial

height

The work done for change of

position is olso 0, as final position

= initial position .

Hence net work done, W = w_{1}

∴ W = 2 μ mgScos θ

Commented by Tinkutara last updated on 25/Jul/17

Thanks Sir!