We can work out the gain in GPE of the box. I'm going to take g to be 9.81 however if your qualification takes g to be 10 you'll need to change it in all the workings:
GPE = mgh
= 400 x 9.81 x 10
=39240J
So, the machine has given 39240J of energy to the box.
Therefore the minimum power generated by the motor is:
39240/8=4905W = 4.9 x 10^3 W
Note this is the <em>minimum</em> possible power generated by it and it is almost certain (well completely certain in the real world) that it will generate far more power than that because it will not be 100% efficient.
Answer: A sealed calorimeter is a closed system because thermal energy is not transferred to the environment.
A closed system is an isolated system where there is no transfer of energy with its surroundings. Also the system is not subjected to any external force whose source is external to the system.
B Coarse, infertile soil is usually found near the base of a mountain<span />
The answer is 259.2 .... divide 360 by 100 and then that answer times 72.