Question

If the power of a motor is $40kW$, at what speed can it raise a load of $20,000N$?

• A. $0.2m{s}^{-1}$
• B. $2m{s}^{-1}$
• C. $20m{s}^{-1}$
• D. None of the above

Answer 1

The correct option is B $2m{s}^{-1}$

$Power=work/time$
$Work=F\times S$
$Power=F\times S/t$
$Power=F\times v$ where $v$ is the velocity as it is rate of change of displacement
$40000=20000\times v$
$v=40000/20000=2m/s$.