The kinetic energy K of a particle moving in a straight line depends on the distances as `K =as^2`. The force acting on the particle is
(where a is a constant) 

Options

A. 2as
B. as
C. 2a
D. `sqrt(as^2)`

Answer

A

Explanation

Here kinetic energy `K = 1/2 mv^2 = as^2`
`:. mv^2 = 2as^2`
Differentating eqn .(i) w.r.t time t, we get
`2 mv (dv)/(dt) = 4as (ds)/(dt) = 4 asv " or " m (dv)/(dt) = 2as` .