Physics help needed..questions about energy.?

Question

when you bounce on a trampoline, , how do you increase your total mechanical energy?

how is hydroelectric energy a form of solar energy?

If a force is in the negative direction, then the work it does is negative, true or false?

what kind of quantity is the kilowatt hour?

Answer 1

on a trampoline the trampoline takes in the energy from your landing then releses it to return to its origanel strength like a catapult

Answer 2

You increase your total mechanical energy on a trampoline by jumping in such a manner that you send energy into the elastic cords which hold the mat. It is the same idea as pumping up a swing. you use your muscles to put energy into the system.

Hydroelectric is a form of solar because solar energy evaporates the water which falls as rain and is trapped behind the dam to generate electricity.

Force does work regardless of the direction,  it takes work to change the velocity of a car whether to speed up or slow down.

A killowatt hour is a measure of electrical output equal to

3,600,000 joules. see the link below for details.