Question

The displacement ' $x$ ' (in meter) of a particle of mass ' $m$ ' (in $kg$ ) moving in one dimension under the action of a force, is related to time ' $t$ ' (in sec) by, $t =\sqrt{ x }+3$. The displacement of the particle when its velocity is zero, will be

• A. 6 m
• B. 2 m
• C. 4 m
• D. 0 m

Answer 1

Answer: (D)

$
\begin{array}{l}
t=\sqrt{x}+3 \\
\Rightarrow x=(t-3)^{2}
\end{array}
$
$
\begin{array}{l}
v=\frac{d x}{d t}=2(t-3) \\
v=0 \Longrightarrow t=3
\end{array}
$
At $t=3, x=(3-3)^{2}=0$