Question

How many slices of bread did each climber have to eat to compensate for the increase of the gravitational potential energy of the system climbers-Earth? (One piece of bread releases about 1.0×106J of energy in the body.) Assume that the height of Mt. Everest is 8850 m, the weight of a person is about 79 kg , and efficiency in converting the body's chemical energy into mechanical work is 9.5 %.

Answer 1

Answer:

Each climber had to eat 72 slices of bread to compensate for the increase of the gravitational potential energy of the system climbers-Earth

Explanation:

Hi

One piece of bread releases about $1.0 \times 10^{6}J$ of energy in the body, but efficiency in converting the body's chemical energy into mechanical work is 9.5 %, so $1.0 \times 10^{6}J(9.5\%)=95\times 10^{3} J$.

On the other hand, we need to calculate the total work to reach the top of Mt. Everest , so $W=mgh=(79 Kg)(9.8 m/s^{2})(8850 m)=6.8 \times 10^{6}J$

Finally, we have that $\# slices=\frac{W}{Energy/Slice} =\frac{6.8 \times 10^{6}J}{95\times 10^{3} J} =72 \ slices \ of \ bread$