### Gravitation class 11 important questions

GRAVITATION
Important questions
Topics to be focused in this lesson
• Newtons law of gravitation
• Kepler's laws
• Acceleration due to gravity
• Orbital velocity and Escape velocity
• Gravitational potential and potential energy
• Kinetic and Total gravitational energy

1. Derive an expression for the variation of acceleration due to gravity above and below the surface of the Earth.
2. Explain Kepler’s law with necessary diagrams.
3. What is orbital velocity? Show that orbital velocity is independent of mass of the body.
4. What is escape velocity? Obtain an expression for it and what is the value of escape velocity of the Earth.
5. Hydrogen is in abundance around the sun but not around earth. Explain
6. The magnitude of the force of gravity between two identical objects is given by F. If the mass of each object is doubled but the distance between them is halved, then find the new force of gravity between the objects.
7. The ratio of mean distances of three planets from the sun is 0.5:1:1.5, then the square of time periods is in the ration of
8. Two spherical balls each of mass 1 kg are placed 1 cm apart. Find the gravitational force of attraction between them
9. Define gravitational potential and obtain the an expression for the gravitational potential at a point on the earth surface.
10. Obtain the expression for the acceleration due gravity at certain height and depth and discuss the variation of the acceleration due to gravity (g) value.
11. Explain about the change in acceleration due to gravity if the rotation of the earth changes.
12. Dimensional formula of universal gravitational constant.
13. What is the orbital velocity of satellite revolving near to the earth surface?
14. Write the ratio between P.E, K.E and T.E at a point on the earth surface.
15. What is areal velocity and show that it is a constant for the particle moving in central force field/gravitational field.
16. Give the abbreviation GSLV.