Q1.Why is gravitational potential energy always negative?[1]

Q2.At what height above the surface of the earth value of acceleration due to

gravity is reduced to one fourth of its value on the surface of the earth?[1]

Q3.Name two factors which determine whether a planet has atmosphere or not?[1]

Q4.What is kepler’s law of periods? Show it mathematically?[2]

Q5.With two characteristics of gravitational force?[2]

Q6.Assuming earth to be a uniform sphere finds an expression for density of earth

in terms of g and G?[2]

Q7.If radius of earth is 6400km, what will be the weight of 1 quintal body if taken

to the height of 1600 km above the sea level?[2]

Q8.A satellite is revolving is a circular path close to a planet of density P. find an

expression for its period of revolution?[3]

Q9.How far away from the surface of earth does the value of g is reduced to 4% of

its value on the surface of the earth Given radius of earth = 6400km..[3]

10.Obtain on expression showing variation of acceleration due to gravity with height?[3]