Q75 of 146 Page 148

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.

Work done is zero, as force and displacement are at 90∘ to each other. And we know that Cos 90° is 0.


More from this chapter

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73

What should be the angle between the direction of force and the direction of motion of a body so that the work done is zero?

 74

In which of the following case the work done by a force will be maximum: when the angle between the direction of force and direction of motion is 0o or 90o?

 76

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?

 77

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