Question

The displacement of particle is given by the relation $t=\sqrt{x-4}$ where $x$ is in meters and $t$ is in seconds. The displacement of particle when its velocity is zero is:

• A. $12m$
• B. $8m$
• C. $4m$
• D. $6m$

Answer 1

The correct option is C $4m$

Given $t=\sqrt{x-4}$

$x=t^2+\mathrm{4......}\left(i\right)$

Then $v=\frac{dx}{dt}=\frac{d}{dt}\left(x\right)$

$=\frac{d}{dt}(t^2+4)$

$=2t$

when $v=0,2t=0$

$t=0$

Putting value of t in (i), we get

$x=4m$