Answer
a) $97 \ W$
b) $11,000 \ W$
Work Step by Step
We know that the average power is equal to the change in work over the change in time. Thus, we find:
a) $P_{avg} = \frac{1300 \times 9.81 \times 55}{2 \times 3600} = 97 \ W$
b) $P_{avg} = \frac{1300 \times 9.81 \times 1500}{.5 \times 3600} = 11,000 \ W$