Q: The change in the value of g at a height h above the surface of earth is the same as at a depth d below the earth. When both d and h are much smaller than the radius of earth, then which one of the following is correct?
Q: A mass of 6 × 1024 kg (equal to the mass of the earth) is to be compressed in a sphere in such a way that the escape velocity from its surface is 3 × 108 ms-1 . What should be the radius of the sphere ?
Q: If the mass of earth were 4 times the present mass, the mass of the moon were half the present mass and the moon were revolving round the earth at twice the present distance, the time period of revolution of the moon would be (in days)