When a ball is thrown vertically upwards, its velocity goes on decreasing. What happens to its potential energy as its velocity becomes zero?

How much work is done by the gravitational force of earth acting on a satellite moving around it in a circular path? Give reason for your answer.

A man is instructed to carry a package from the base camp at B to submit A of a hill at a height of 1200 metres. The man weighs 800 N and the package weighs 200 N. If g = 10 m/s²,

(i) How much work does man do against gravity?

(ii) What is the potential energy of the package at A if it is assumed to be zero at B?

A man X goes to the top of a building by a vertical spiral staircase. Another man Y of the same mass goes to the top of the same building by a slanting ladder. Which of the two does more work against gravity and why?

When a ball is thrown inside a mocking bus, does its kinetic energy depend on the speed of the bus? Explain.