The force of attraction between two masses each of 1 kg kept at a separation of 1 m is —

1. 9.8 N
2. 6.7 N
3. 980 N
4. 6.7 x 10^-11 N

The gravitational force of attraction between two bodies of masses 60 kg and 40 kg separated by a distance 10 m is : (where G = 6.7 x 10^-11 Nm²kg^-2 )

1. 1.60 x 10^-9 N
2. 2.8 x 10^-11 N
3. 1.0 x 10^-11 N
4. 1.6 x 10^-11 N

The value of g on a planet depends on :

1. the mass of the planet
2. the radius of the planet
3. both (a) and (b)
4. composition of the planet