Question

A particle of mass 0.2 kg is moving in one dimension under a force that delivers a constant power 0.5 W to the particle. If the initial speed (in m/s) of the particle is zero, the speed (in $m{s}^{-1}$) after 5 s is

Answer 1

Work done =Fs=ma s

$w=\frac{m}{2}2as=\frac{m{v}^2}{2}$

Power $p=\frac{dw}{dt}$

$w=\int pdt={\int }_0^{5}0.5dt$

$\frac{m{v}^2}{2}=0.5\stackrel{5}{\underset{0}{\left[t\right]}}v=\sqrt{\frac{0.5\times 5\times 2}{0.2}}=5m$