## Essential University Physics: Volume 1 (3rd Edition)

a) $76,072$ b) $13,947\ W$
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: $P =\frac{W}{\Delta t}=\frac{836800}{60}=13,947\ W$