Question

1 What is the gravitational field strength at a height h above the surface of the Earth? R is the radius of the earth
gR2(R+h)2
gR(R+h)
Rg(R−h)
R2g(R−h)2

2 The instrument used for experimental determination of the value of the universal gravitational constant G is called
Galilio’s telescope
ballistic pendulum
Newton’s balance
Cavendish balance

3 At what altitude above the earth's surface would the acceleration due to gravity be 49ms−2? Assume the mean radius of the earth is 64106 metres and the acceleration due to gravity 98ms−2 on the surface of the earth
26106m
323106m
465