11.A satellite in a circular orbit of radius R has period 4 hours. A satellite of orbit radius 4R around the same planet will have period

12.Masses of 1 kg each are placed 1 m, 2m, 4 m, 8 m,��from a point P. The gravitational field intensity at P due to these masses is

13.An object weighs 98 N at the north pole of Earth. What is its true weight in a geostationary satellite whose distance from the centre of Earth is 7R, where R is the radius of the Earth ?

14.If Earth describes an orbit round the Sun of double its present radius, the year on Earth will be of

15.A satellite is launched in a circular orbit of radius R and another satellite is launched in circular orbit of radius 1.01 R. The time period of second satellite is different from that of the first satellite by