Question

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 $t=\sqrt{x}+3\forall t\in [3,\infty )$, where $x$ is in metres and $t$ is in seconds.
The displacement of the particle when its velocity is zero is

• A. 0
• B. 6m
• C. 12m
• D. 18m

Answer 1

Answer: (A)

0

$t=\sqrt{x}+3$
$\Rightarrow x=(t-3{)}^2$

$v=\frac{dx}{dt}=2(t-3)$
$v=0⟹t=3$
$Att=3,x=(3-3{)}^2=0$