Answer
(a) $W = 1.10\times 10^5~J$
(b) $W = 1.30\times 10^5~J$
(c) $P = 4000~W$
Work Step by Step
(a) $W = mgh$
$W = (800~kg)(9.80~m/s^2)(14.0~m)$
$W = 1.10\times 10^5~J$
(b) $W = \frac{1}{2}mv^2$
$W = \frac{1}{2}(800~kg)(18.0~m/s)^2$
$W = 1.30\times 10^5~J$
(c) $P = \frac{W_{tot}}{60~s}$
$P = \frac{1.10\times 10^5~J+1.30\times 10^5~J}{60~s}$
$P = 4000~W$