Hello. I have questions about physics.

You release a pendulum of mass 1 kg from a height of 0.75 m.

a. If there is no air resistance, how fast is the pendulum going when it reaches the bottom?

b. If the pendulum loses 18% of its initial energy by the time it reaches the bottom, how fast is it going when it reaches the bottom?

c. If the pendulum loses another 7% of its remaining energy by the time it reaches the other side, how high up does it go?

d. After a few minutes, the pendulum is no longer swinging at all. Explain why this happens, in terms of energy.