Answer
(a) The average power that must be delivered by the motor is $2620~Watts$
(b) The average power that must be delivered by the motor is $7850~Watts$
Work Step by Step
(a) Let $m_1 = 1202~kg$ and let $m_2 = 801~kg$.
We can find the energy $E$ that the motor must provide:
$E = m_1gh - m_2gh$
$E = (m_1 - m_2)~gh$
$E = (1202~kg - 801~kg)~(9.80~m/s^2)(40.0~m)$
$E = 1.57\times 10^5~J$
We can find the average power output:
$Power = \frac{Energy}{Time} = \frac{1.57\times 10^5~J}{60~s} = 2620~Watts$
The average power that must be delivered by the motor is $2620~Watts$
(b) We can find the energy $E$ that the motor must provide:
$E = m_1gh$
$E = (1202~kg)(9.80~m/s^2)(40.0~m)$
$E = 4.71\times 10^5~J$
We can find the average power output:
$Power = \frac{Energy}{Time} = \frac{4.71\times 10^5~J}{60~s} = 7850~Watts$
The average power that must be delivered by the motor is $7850~Watts$.
