A ball is dropped from a satellite revolving around the earth at a height of 120 km. The ball will
continue to move with the same speed along a straight line tangentially to the satellite at that time.
continue to move with the same speed along the original orbit of the satellite
fall down to earth gradually
go far away in space
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' = 9 g
g' = 27g
A body attains a height equal to the radius of the earth. The velocity of the body with which it was projected is
The distances of two planets from the sun are 1013 m and 1012 m respectively. The ratio of time periods of these two planets is
1/√10
100
10 √10
√10
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 statement 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 time period.
The kinetic energies of the two satellites are equal.
A roller coaster is designed such that riders experience "weightlessness" as they go round the top of a hill whose radius of curvature is 20 m. The speed of the car at the top of the hill is between
14 m/s and 15 m/s
15 m/s and 16 m/s
16 m/s and 17 m/s
13 m/s and 14 m/s
What will be the formula of the mass in terms of g, R and G? (R = radius of earth)
g2 R/G
G R2/g
G R/g
g R2/G
A planet is moving in elliptical orbit around the sun. If T, U, E and L stand for its kinetic energy, gravitational potential energy, total energy and magnitude of angular momentum about the centre of force, which of the following is correct?
T is conserved.
U is always positive.
E is always negative.
L is conserved but direction of vector L changes continuously.
A body of mass m is placed on earth's surface. It is then taken from earth's surface to a height h = 3R, then the change in gravitational potential energy is
A seconds pendulum is mounted on a rocket. Its period of oscillation decreases when the rocket
comes down with uniform acceleration.
moves round the earth in a geostationary orbit.
moves up with a uniform velocity.
moves up with uniform acceleration.
