Question from the text book ( I P E )

1. State the unit and dimension of the universal gravitational constant (G). Answer

2. State the vector form of Newton's law of gravitation. Answer

3. If the gravitational force of Earth on the moon is F, what is the gravitational force of moon on earth? Do these forces form an action-reaction pair? Answer

4. What would be the change in acceleration due to gravity (g) at the surface, if the radius of Earth decreases by 2% keeping the mass of the Earth constant? Answer

5. As we go from one planet to another, how will a) the mass and b) the weight of a body change? Answer

6. Keeping the length of a simple pendulum constant, will the time period be the same on all planets? Support your answer with reason. Answer

7. Give the equation for the value of g at a depth d from the surface of Earth. What is the value of g at the centre of Earth? Answer

8. What are the factors that make g the least at the equator and maximum at the poles? Answer

9. "Hydrogen is in abundance around the sun but not around earth". Explain. Answer

10. What is the time period of revolution of a geostationary satellite? Does it rotate from West to East or from East to West? Answer

11. What are polar satellites? Answer

Short Answer Questions (4 Marks)

1. State Kepler's laws of planetary motion. Answer

2. Derive the relation between acceleration due to gravity(g) at the surface of a planet and gravitational constant(G). Answer

3. How does the acceleration due to gravity ( g ) change for the same values of height ( h ) and depth ( d )? Answer

4. What is orbital velocity? Obtain an expression for it. Answer

5. What is escape velocity? Obtain an expression for it. Answer

6. What is a geostationary satellite? State its uses. Answer

7. If two places are at the same height from the mean sea level, one is a mountain and other is in air. At which place will g be greater? State the reason for your answer. Answer

8. The weight of an object is more at the poles than at the equator. At which of these can we get more sugar for the same weight? State the reason for your answer. Answer

9. If a nut becomes loose and gets detached from a satellite revolving around the earth, will it fall down to earth or will it revolve around earth? Give reasons for your answer. Answer

10. An object projected with a velocity greater than or equal to 11.2 km.s⁻¹ will not return to earth. Explain the reason. Answer

Long Answer Questions (8 Marks)

1. Define gravitational potential energy and derive an expression for it associated with two particles of masses m₁ and m₂. Answer

2. Derive an expression for the variation of acceleration due to gravity (a) above and (b) below the surface of the Earth. Answer

3. State Newton's Universal Law of Gravitation. Explain how the value of the Gravitational constant (G) can be determined by Cavendish method. Answer-I & Answer -II