According to one of the Kepler’s laws of planetary motion:

A. r²∝ T³ B. r∝ T²

C. r³∝ T² D. r³∝

The gravitational force of attraction between two objects is x, Keeping the masses of the objects unchanged, if the distance between the objects is halved, then the magnitude of gravitational force between them will become:

A. x/4 B. x/2

C. 2x D. 4x

An apple of mass 100 g. falls from a tree because of gravitational attraction between the earth and the apple. If the magnitude of force exerted by the earth on the apple be F1 and the magnitude of force exerted by the apple on the earth be F2 then:

A. F1 is very much greater than F2

B. F2 is very much greater then F1

C. F1 is only a little greater than F2

D. F1 and F2 are exactly equal

If the distance between two masses is increased by a factor of 5, by what factor would the m ass of one of them have to be altered to maintain the same gravitational force? Would there be an increase or decrease in the mass?

Universal law of gravitation states that every object exerts a gravitational force of attraction on every other object. If this is true, why don’t we notice such forces? Why don’t the two objects in a room move towards each other due to this force? (Picture)