Question

A body of mass $2kg$ starts from rest with a constant power of $25$ watt, if velocity of the body is $3m/s$ then find the displacement.

Answer 1

$P=F.V$
$a=\frac{F}{m}=\frac{P}{mv}$
$v.dv=adx$
$v.dv=\int \left(\frac{P}{mv}\right)dx$
$\frac{v^3}{3}=\frac{P}{m}x$
$\left(\frac{3\times 3\times 3}{3}\right)=\frac{25}{2}\times x$
$x=\frac{18}{25}m$