If suddenly the gravitational force of attraction between the earth and a satellite revolving around it becomes zero, then the satellite will?
A.
Continue to move in its orbit with the same velocity
B.
Move tangentially to the original orbit with the same velocity
C.
Become stationary in its orbit
D.
Move towards the earth
Answer: Option B
Explanation:
If the gravitational force suddenly becomes zero, the satellite will move tangentially to the original orbit with the velocity, it was revolving around the earth.
Gravitational law is also called universal law because of the fact that the law of gravitation holds good for any pair of bodies in the universe whether microscopically small or astronomically large in size.
If the diameter if the earth becomes twice its present value but its mass remains unchanged, then how would be the weight of an object on the surface of the earth affected?
A.
1/2 W
B.
1/3 W
C.
1/4 W
D.
W
Answer: Option C
Explanation:
Weight of the body, W=mg=GMm/R2 When the diameter or radius of the earth becomes double its present value, the weight of the body will be W’=GMm/((2R)2 )=1/4 W That is, the weight will become one-fourth of the present value.
At which part of the earth’s surface, the value of g is largest?
A.
At the equator
B.
Immediately below the equator
C.
Immediately above the equator
D.
At the poles
Answer: Option D
Explanation:
Distance of poles from the centre of the earth is smaller than the distance of any other point on the earth’s surface from its centre. At poles, no centrifugal force acts on the body. Hence the value of g is largest at the poles.
