Worksheet
Chapter- Gravitation
1. What is the SI unit of Universal Gravitational Constant?
2. With what velocity should a body be thrown up so that it rises to a height equal to the
radius of the earth?
3. Can gravitational potential have positive value?
4. An elephant and an ant are to be projected out of the gravitational pull of the earth. Do
we need different velocities to achieve so?
5. What is the weight of the body at the centre of the earth?
6. Define escape velocity. Derive an expression for the escape velocity of a body from
the surface of Earth.
7. Define acceleration due to gravity and show that gravity decreases with depth.
8. Discuss the variation of g with altitude.
9. A mass M is broken into two parts, m and (M-m). How is m related to M so that the
gravitational force between these two parts is maximum?
10. According to Newton’s law of gravitation every particle of matter attracts every other
particle. But bodies on the surface of the earth never move towards each other on
account of this force of attraction. Why?
11. An artificial satellite revolving around the earth does not require any fuel. On the
other hand, aeroplane requires fuel to fly at a certain height. Why?
12. What is gravitational potential energy? Derive its expression for the mass located at a
distance r from the centre.
For Numerical refer to NCERT.
Deleted questions from exercise: 8.1, 8.3 (iii), 8.4, 8.6, 8.10, 8.11, 8.20.
