Question

The displacement of $x$ of a particle moving in one dimension is related to time by the equation $t=(\sqrt{x}+3)$, where $x$ is in $m$ and $t$ in $s$. The displacement, when velocity is zero, is

• A. $1m$
• B. $2m$
• C. $4m$
• D. $zero$

Answer 1

The correct option is D $zero$

It is given that
$t=\sqrt{x}+3\Rightarrow x={(t-3)}^2=t^2+9-6t$

Now,
$\frac{dx}{dt}=v=2t-6=0\Rightarrow t=3seconds$

Now put $t=3$seconds
$\Rightarrow x=0meters$