Question

A time $t=0s$ a particle starts moving along the x-axis. It its kinetic energy increases uniformly with time $t$, the net force acting on it must be proportional to

• A. $\frac{1}{\sqrt{t}}$
• B. $\sqrt{t}$
• C. $constant$
• D. $t$

Answer 1

The correct option is A $\frac{1}{\sqrt{t}}$

$\frac{1}{2}m{v}^2=kt$
$a=\frac{dv}{dt}=k^{\prime }\frac{1}{2}\frac{1}{\sqrt{t}}$
$F\propto a\propto \frac{1}{\sqrt{t}}$