There are many forms of energy, but they can all be put into two categories: kinetic and potential. Kinetic energy is motion––of waves, electrons, atoms, molecules, substances, and objects. Potential energy is stored energy and the energy of position––gravitational energy
Answer:
to prevent the derailing of the train due to thermal expansion.
Answer:
(1) 10^−2 m
Explanation:
The diameter of the tire of an automobile is generally expressed in centimetres; we can say that the diameter of a tire is generally about
d = 20 cm (20 centimetres)
Now we have to verify which option is closest to this value. To do that, we have to keep in mind the equivalence between metres and centimetres; in fact, we have:

This means that we can rewrite the diameter of the tire of a car as

By comparing it with the given options, we see that the closest option is
(1) 10^−2 m
which is therefore the correct answer.
The potential energy that the ball has at the top of the tower is its kinetic energy when it hits the ground. The second ball has more potential energy at the top, because you did more work on it to carry it up there. So it has more KE at the bottom. (A)