Hydroelectric energy is based on the of water being converted to as water falls and pushes against the turbine.
kinetic; potential
potential; kinetic
chemical; electric
mechanical; chemical

Hydroelectric energy is based on the potential energy of water being converted to kinetic energy as water falls and pushes against the turbine.

Explanation:

Initially, the water is at the top of its trajectory. At this moment the water possesses gravitational potential energy due to its height relative to the ground. The gravitational potential energy is given by:

where m is the mass of the water, g is the gravitational acceleration, and h is the heigth of the water relative to the ground.

As the water falls, the height h increases, and the gravitational potential energy decreases, being converted into kinetic energy, since the water gains speed. In fact, the kinetic energy is given by

where v is the water's speed. At the bottom of its trajectory, all the gravitational potential energy has been converted into kinetic energy: now the water flows through the turbines, pushing them and making them rotating, and this energy will be converted into electrical energy.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.