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If the kinetic energy of a satellite orbiting around the earth is doubled then

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Important Questions on Gravitation

EASY
A body is projected upwards with a velocity of 4×11.2 km s-1 from the surface of earth. The velocity of the body when it escapes the gravitational pull of earth is
MEDIUM
Two satellites, A and B, have masses m and 2m respectively. A is in a circular orbit of radius R and B is in a circular orbit of radius 2R around the earth. The ratio of their kinetic energies, KAKB is:
EASY
For a satellite moving in an orbit around the earth, the ratio of kinetic energy to potential energy is
MEDIUM
The kinetic energies of a planet in an elliptical orbit about the Sun, at positions, A, B and C are KA, KB and KC, respectively. AC is the major axis and SB is perpendicular to AC at the position of the Sun S as shows in the figure. Then

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EASY
A satellite is orbiting the Earth in a circular orbit of radius R . Which one of the following statements is true?
HARD

A body is projected vertically upwards from the surface of earth with a velocity sufficient enough to carry it to infinity. The time taken by it to reach height h is           S.

EASY
Binding energy of a revolving satellite at height h is 3.5×108 J. Its potential energy is
EASY
A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth. Then,
MEDIUM
The energy required to take a satellite to a height h above the Earth surface (radius of Earth =6.4×103 km ) is E1, and the kinetic energy required for the satellite to be in a circular orbit at this height is E2. The value of h for which E1 and E2 are equal, is
HARD
An asteroid is moving directly towards the centre of the earth. When at a distance of 10R (R is the radius of the earth) from the centre of the earth, it has a speed of 12 km s-1. Neglecting the effect of earth's atmosphere, what will be the speed of the asteroid when it hits the surface of the earth (escape velocity from the earth is 11.2 km s-1) ? Give your answer to the nearest integer in km s-1__________.
HARD
A body is thrown from the surface of the earth with velocity u m s-1. The maximum height in meter above the surface of the earth up to which it will reach is (R= radius of the earth, g= acceleration due to gravity)
MEDIUM
A stationary object is released from a point P a distance 3R from the centre of the moon which has radius R and mass M. Which one of the following expressions gives the speed of the object on hitting the moon?
HARD
Two stars of masses 3×1031 kg each, and at distance 2×1011 m rotate in a plane about their common centre of mass O. A meteorite passes through O moving perpendicular to the star's rotation plane. In order to escape from the gravitational field of this double star, the minimum speed that meteorite should have at O is ( Take Gravitational constant G=6.67×10-11 N m2 kg-2 )
HARD

Suppose two planets (spherical in shape) of radii R and 2R, but mass M and 9M respectively have a centre to centre separation 8R as shown in the figure. A satellite of mass m is projected from the surface of the planet of mass M directly towards the centre of the second planet. The minimum speed v required for the satellite to reach the surface of the second planet is a7GMR, then the value of  a is
[Given : The two planets are fixed in their position]

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EASY
A remote-sensing satellite of earth revolves in a circular orbit at a height of 0.25×106 m above the surface of earth. If earth's radius is 6.38×106 m and g=9.8 s-2, then the orbital speed of the satellite is:
EASY
If the axis of rotation of the earth were extended into space then it would pass close to -
EASY
The relative uncertainty in the period of a satellite orbiting around the earth is 10-2 . If the relative uncertainty in the radius of the orbit is negligible, the relative uncertainty in the mass of the earth is:
EASY
A satellite is orbiting close to the earth and has a kinetic energy K. The minimum extra kinetic energy required by it to just overcome the gravitation pull of the earth is
EASY
The ratio of the binding energy of a satellite at rest on earth's surface to the binding energy of a satellite of same mass revolving around the earth at a height h above the earth's surface is (R= radius of the earth).
MEDIUM
What is the minimum energy required to launch a satellite of mass m from the surface of a planet of mass M and radius R in a circular orbit at an altitude of 2R ?