An electric motor exerts a force of $50 \mathrm{~N}$ on a a cable and pulls it through $60 \mathrm{~m}$ in…
An electric motor exerts a force of $50 \mathrm{~N}$ on a a cable and pulls it through $60 \mathrm{~m}$ in $1 \mathrm{~min}$. The power supplied by the motor is
$50 \mathrm{~W}$
$3000 \mathrm{~W}$
$1 \mathrm{~W}$
$100 \mathrm{~W}$
Solution
Force exerted by electric motor,
$
F=50 \mathrm{~N}
$
Displacement, $s=60 \mathrm{~m}$
Time, $t=1 \mathrm{~min}=60 \mathrm{~s}$
$\therefore$ Power supplied by the motor,
$
\begin{array}{rlr}
P & =\frac{W}{t}=\frac{F \times s}{t} & {[\because W=F s]} \\
& =\frac{50 \times 60}{60}=50 \mathrm{~W} &
\end{array}
$