Answer
a) $ 76,072$
b) $13,947\ W$
Work Step by Step
a) We know that one kcal is 4184 Joules. Thus, we find:
$W = 200\times 4184 = 836800$
We now find how many reps this will take:
$836800=(20)(.55)(x) \\ x = 76,072$
b) We find the average power output:
$P =\frac{W}{\Delta t}=\frac{836800}{60}=13,947\ W$
