The displacement x of a particle moving in

Your Ultimate Guide to JEE & NEET Question Solutions

The displacement $x$ of a particle moving in one dimension under the action of a constant force is related to the time t by the equation $t = \sqrt x + 3$, where $x$ is in meters and $t $ is in seconds. The work done by the force in the first $ 6$  seconds is.....$J$

A

$9$

B

$6$

C

$0$

D

$3 $

The displacement $x$ of a particle moving in one dimension under the action of a constant force is related to the time t by the equation $t = \sqrt x + 3$, where $x$ is in meters and $t $ is in seconds. The work done by the force in the first $ 6$  seconds is.....$J$

$x = {(t - 3)^2}$==> $v = \frac{{dx}}{{dt}} = 2(t - 3)$
at $t = 0$; ${v_1} = - 6\,m/s$ and at $t = 6\,\sec $, ${v_2} = 6\,m/s$
so, change in kinetic energy$ = W = \frac{1}{2}mv_2^2 - \frac{1}{2}mv_1^2 = 0$