Plz help me in Science questions???????

Question

1. How do the different forms of potential energy depend on an object's position or chemical composition?

2. What forms of potential energy would be found in an apple on the branch of a tree? Explain.

3. Describe a stone falling off a tabletop in terms of both kinetic energy and potential energy?

PLEASE ANSWER A GOOD QUESTION BECAUSE IF I DIDN'T ANSWER GOOD...THE TEACHER WILL TAKE POINTS OFF....PLZ

Answer 1

1.There can be different forms of potential energy in a body. The potential energy of gravity means that the body can fall down and its gravity potential energy will become its kinetic energy. So the potential energy of gravity becomes greater when the distance between masses increases. The same is for electrical negatively and positively charged bodies. And for two positively or two negatively charged bodies potential energy increases when we approach the bodies together.
The body’s chemical composition also means some energy in it, thus the explosive can explode and the potential chemical energy will become kinetic, or for example a mixture of hydrogen and oxygen under normal conditions, or even radioactive element can react and energy will appear.
2.We can suppose that the apple is electrically neutral, and we shall not consider chemical composition and possible chemical potential energy in the apple. We can find potential gravity energy for the apple – Earth pair of forces, and also for apple – Sun pair of forces, and also apple – Moon, apple – a star, and for all other gravity objects.
3.When a stone is falling on a tabletop, its potential energy is
mgh,
here m is the stone’s mass, g is a gravity acceleration, and h is the stones height from the level of the table. It’ kinetic energy is
mV^2/2,
where v is its speed. In case the speed is not only vertical, then V^2/2 = Vv^2/2 + Vh^2/2,
Vv is vertical component of speed, and Vh is horizontal component of speed. Loosing its height, the stone increases its vertical component of speed, so that
mgh + mV^2/2 = const.,
Vh = const. (because there is no force along any of horizontal directions), and thus
mgh +mVv^2/2 = const.
If a stone falls from the initial height H and with zero initial vertical velocity, then
mgh + mVv^2/2 = conct = mgH,
and at the moment the stone comes to the table (h=0), it has the vertical velocity Vvo:
0 + mVvo^2/2 = mgH,
Vvo = sq.root{2gH}.