Answer:
Part a)
[tex]P = 186 W[/tex]
Part B)
[tex]N = 676 times[/tex]
Explanation:
Part a)
Average power is rate of energy consumption
So it is given as
[tex]P = \frac{mgh}{t}[/tex]
[tex]P = \frac{100(75.7)(9.81)(0.150)}{59.9}[/tex]
[tex]P = 186 W[/tex]
Part b)
If the efficiency is given as
[tex]\eta = 20[/tex]%
so we know that 20% of total energy consumed is converted into output work
So total power consumed here will be given as
[tex]P = \frac{186}{0.20}[/tex]
[tex]P = 930 W[/tex]
Energy consumed by him
[tex]E = power \times time[/tex]
[tex]E = 930 \times 59.9[/tex]
[tex]E = 55707 J[/tex]
now we know that 1 g fat will release 9 Calories energy
So we have
[tex]1 g = 9 \times 4184 J[/tex]
[tex]1 g = 37656 J[/tex]
so to consume 1000 g of fat we need to release total energy
[tex]E = 37656 \times 10^3 J[/tex]
so total number of times
[tex]N = \frac{37656 \times 10^3}{55707}[/tex]
[tex]N = 676 times[/tex]