Question

Force acting on a particle moving in a straight line varies with the velocity of the particle v as F = `K/v`, where K is a constant. The work done by this force in time t is

Options

• `K/v^2 t`

• `(2K)/v^2 t`

• Kt

• 2Kt

Answer 1

Kt

Explanation:

F = `K/v`

∴ W = Fs cos θ

∴ W = `K/v s`  ......(∵ θ = 0°)

But velocity (v) = `("displacement"  (s))/("time" (t))`

∴ W = `K xx t/s xx s`

∴ W = Kt