Well they could go down a hill to gain more kinetic energy.
The answer is true due to the fact that "peak" is another way of saying "top" and in this case its the MAX number of people traveling.
The answer is A) 1000 J
According to the law of conservation of energy, the total energy before an action is always equal to the total energy after the action.
So that is, the total energy is 8000J found as potential energy, 7000J has transformed into kinetic energy, then the thermal energy should be the remaining 1000J.
Hope this helps.
C.water vapor i hope i helped