EASY

Earn 100

Define orbital velocity of a satellite.

Important Questions on Gravitation

EASY

Physics>Mechanics>Gravitation>Earth Satellites

A remote-sensing satellite of earth revolves in a circular orbit at a height of

0.25 \times 10^{6}

m above the surface of earth. If earth's radius is

6.38 \times 10^{6} m

and

g = 9.8 m s^{- 2}

, then the orbital speed of the satellite is:

EASY

Physics>Mechanics>Gravitation>Earth Satellites

A body is moving in a low circular orbit about a planet of mass

M

and radius

R

. The radius of the orbit can be taken to be

R

itself. Then the ratio of the speed of this body in the orbit to the escape velocity from the planet is:

EASY

Physics>Mechanics>Gravitation>Earth Satellites

A satellite is launched to a distance

r

from the centre of the earth to have a circular orbit around the earth. Its orbital velocity to maintain this orbit is (mass of the earth as

M_{E}

)

HARD

Physics>Mechanics>Gravitation>Earth Satellites

Two satellites

A

and

B

of masses

200 kg

and

400 kg

are revolving round the earth at height of

600 km

and

1600 km

respectively. If

T_{A}

and

T_{B}

are the time periods of

A

and

B

respectively then the value of

T_{B} - T_{A}

Question Image

[ Given : radius of earth $= 6400 km,$ mass of earth $= 6 \times 10^{24} kg$ ]

MEDIUM

Physics>Mechanics>Gravitation>Earth Satellites

A satellite is revolving in a circular orbit at a height

h

from the earth's surface (radius of earth

R

;

h << R

). The minimum increase in its orbital velocity required, so that the satellite could escape from the earth's gravitational field, is close to (Neglect the effect of atmosphere.)

MEDIUM

Physics>Mechanics>Gravitation>Earth Satellites

Which of the following is not true about the total lunar eclipse?

EASY

Physics>Mechanics>Gravitation>Earth Satellites

A planet is moving in a circular orbit. It completes

2

revolutions in

360 days

. What is its angular frequency?

MEDIUM

Physics>Mechanics>Gravitation>Earth Satellites

A geostationary satellite is taken to a new orbit such that its distance from centre of the earth is doubled. Then find the time period of this satellite in the new orbit.

EASY

Physics>Mechanics>Gravitation>Earth Satellites

An astronaut of mass

m

is working on a satellite orbiting the earth at a distance

h

from the earth's surface. The radius of the earth is

R

, while its mass is

M

. The gravitational pull

F_{G}

on the astronaut is

HARD

Physics>Mechanics>Gravitation>Earth Satellites

A test particle is moving in a circular orbit in the gravitational field produced by a mass density

ρ (r) = \frac{K}{r^{2}} .

Identify the current relation between the radius

R

of the particle’s orbit and its period

T :

EASY

Physics>Mechanics>Gravitation>Earth Satellites

Consider two satellites

S_{1}

and

S_{2}

with periods of revolution

1 hr

and

8 hr

respectively revolving around a planet in circular orbits. The ratio of angular velocity of satellite

S_{1}

to the angular velocity of satellite

S_{2}

is:

EASY

Physics>Mechanics>Gravitation>Earth Satellites

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

Physics>Mechanics>Gravitation>Earth Satellites

The time period of an earth satellite in circular orbit is independent of

MEDIUM

Physics>Mechanics>Gravitation>Earth Satellites

Two satellites

A

and

B

are revolving with critical velocities

v_{A}

and

v_{B}

around the earth, in circular orbits of radii

R

and

2 R

respectively. The ratio

\frac{v_{A}}{v_{B}}

MEDIUM

Physics>Mechanics>Gravitation>Earth Satellites

The planet Mars has two moons, if one of them has a period

7

hours,

30

minutes and an orbital radius of

9.0 \times 10^{3} km .

Find the mass of Mars.

\{

Given

\frac{4 π^{2}}{G} = 6 \times 10^{11} N^{- 1} m^{- 2} {kg}^{2}\}

EASY

Physics>Mechanics>Gravitation>Earth Satellites

When a satellite falls to an orbit of smaller radius its kinetic energy

HARD

Physics>Mechanics>Gravitation>Earth Satellites

The distance between two stars of masses $3 M_{S}$ and $6 M_{S}$ is $9 R$ . Here $R$ is the mean distance between the centres of the Earth and the Sun, and $M_{S}$ is the mass of the Sun. Two stars orbit around their common centre of mass in circular orbits with period $n T$ , where $T$ is the period of Earth's revolution around the Sun.

The value of $n$ is _____.

MEDIUM

Physics>Mechanics>Gravitation>Earth Satellites

A spaceship orbits around a planet at a height of

20 k m

from its surface. Assuming that only gravitational field of the planet acts on the spaceship, what will be the number of complete revolutions made by the spaceship in

24

hours around the planet?
[Given: Mass of planet

= 8 \times 10^{22} k g

,
Radius of planet

= 2 \times 10^{6} m,

Gravitational constant

G = 6.67 \times 10^{- 11} N m^{2} / k g^{2}

]

EASY

Physics>Mechanics>Gravitation>Earth Satellites

If the axis of rotation of the earth were extended into space then it would pass close to -

EASY

Physics>Mechanics>Gravitation>Earth Satellites

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,

Define orbital velocity of a satellite.

Important Questions on Gravitation

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