Question

The distance travelled by a particle in a straight line motion is directly proportional to $t^{1 / 2}$, where $t$ is the time elapsed. What is the nature of motion?

• A. Increasing acceleration
• B. Decreasing acceleration
• C. Increasing retardation
• D. Decreasing retardation

Answer 1

Answer: (D)

$s=k t^{1 / 2}$
$\Rightarrow a=\frac{d^{2} s}{d t^{2}}=-\frac{1}{4} k t^{-3 / 2}$
As $t$ increases, retardation decreases.