CBSE
A satellite orbiting the earth in a circular orbit of radius R completes one revolution in 3h. If orbital radius of geostationary satellite is 36000 km, orbital radius of earth is
6000 km
9000 km
12000 km
15000 km
The escape velocity for the earth is 11.2 km/s. The mass of another planet 100 times mass of earth and its radius is 4 times radius of the earth. The escape velocity for the planet is
280 km/s
56.0 km/s
112 km/s
56 km/s
A launching vehicle carrying an artificial satellite of mass m is set for launch on the surface of the earth of mass M and radius R. If the satellite is intended to move in a circular orbit of radius 7R, the minimum energy required to be spent by the launching vehicle on the satellite is (Gravitational constant= G)
For a satellite moving in an orbit around the earth, the ratio of kinetic energy to potential energy is
2
There are two planets and the ratio of radius of the two planets is K but ratio of acceleration due to gravity of both planets is g. What will be the ratio of their escape velocity ?
(kg)1/2
(kg)-1/2
(kg)2
(kg)-2
Imagine a new planet having the same density as that of earth but it is 3 times bigger than the earth in size. If the acceleration due to gravity on the surface of earth is g and that on the surface of the new planet is g', then
g' = 3g
g' = 9g
g' = 27g
Two satellites of earth, S1 and S2 are moving in the same orbit. The mass of S1 is four times the mass of S2. Which one of the following statements is true ?
The time period of S1 is four times that of S2
The potential energies of earth and satellite in the two cases are equal
S1 and S2 are moving with the same speed
The kinetic energies of the two satellites are equal
Change in acceleration due to gravity is same upto a height h from each other the earth surface and below depth x then relation between x and his ( h and x<<<Re )
x = h
x = 2h
x =
x = h2
A uniform ring of mass m and radius a is placed directly above a uniform sphere of mass m and of equal to radius. The centre of the ring is at a distance a from the centre of the sphere. The gravitational force (Fl exerted by the sphere on the ring is
Earth is revolving around the sun. If the distance of the earth from the sun is reduced to 1/4th of the present distance then the length of present day will be reduced by :