Question

If the velocity of a body moving in a straight line is proportional to the square root of the distance traversed, then it moves with

• A. variable force
• B. constant force
• C. zero force
• D. zero acceleration

Answer 1

The correct option is B constant force

Given, velocity $v\propto \sqrt{s}$
$\Rightarrow v=k\sqrt{s}$
$\frac{dv}{dt}=\frac{k}{2\sqrt{s}}\frac{ds}{dt}$
$\Rightarrow a=\frac{k^2}{2}$
Hence, acceleration is constant.
$F=ma$ , so force is also constant.