Answer
(a) $15h$
(b) $0.62\frac{m}{s}$
(c) $1.6s$
Work Step by Step
(a) We know that
$P=\frac{W}{t}$
This can be rearranged as:
$t=\frac{W}{P}$
We plug in the known values to obtain:
$t=\frac{280Cal\times 4186J/Cal}{22W}$
$t=53,300\times \frac{1h}{3600s}$
$t=15h$
(b) As $P=Fv$
This can be rearranged as:
$v=\frac{P}{F}$
$v=\frac{P}{mg}$
We plug in the known values to obtain:
$v=\frac{22}{(3.6)(9.81)}$
$v=0.62\frac{m}{s}$
(c) We can find the required time as
$v=\frac{d}{t}$
$\implies t=\frac{d}{v}$
We plug in the known values to obtain:
$t=\frac{1.0}{0.62}$
$t=1.6s$
