Gravitation

if the density of the earth is doubled keeping its radius constant then the acceleration due to gravity will be

• 2.45 m/s²

• 19.6 m/s²

• 9.8 m/s²

• 4.9 m/s²

The average magnitude of intensity of the gravitational field on the surface of the earth in SI is about:

• 0

• 10

• 100

• more than 100

If the mass and radius of a planet are doubled , then the acceleration due to gravity on its surface will be:

• One fourth

• One half

• Double

• four times

If the radius of earth decreases by 10% , the mass remaining unchanged, what will happen to the acceleration due to gravity?

• Decreases by 19%

• Increases by 19%

• Decreases by more than 19%

• Increases by more than 19%

A body of mass M is taken from the surface of the earth to a height equal to the radius R of the earth. The change in gravitational potential energy is:

• 2MgR

• MgR

• MgR/2

• MgR/4

Which of the following is independent on the mass of the earth?

• Orbital velocity

• Escape velocity

• Gravitational intensity

• None of above

Escape velocity of the air molecules from the surface of the earth is.

• 3.1 Km/s

• 7.9 Km/s

• 11.2 Km/s

• 36 Km/s

To put in orbit, the satellite should be fired as a projectile with:

• Escape velocity

• Twice the escape velocity

• Thrice the escape velocity

• none of above

The relation between the time period and mean radius of the orbit of a planet about the sun is given by

• Newton's law of Gravitation

• Keplar's law

• Law of conservation of momentum

• none of above

As the radius of satellite orbit increases, its time period

• Increases

• Decreases

• Remain constant

• first increases become maximum and then decreases