Class 9 - Practice Level 2 – Gravitation Set 1

Total questions: 25

Calculate the gravitational force between two 50 kg masses separated by a distance of 2 meters. $ \displaystyle \left( {\text{Use }G=6.67\times {{{10}}^{{-11}}}N{{m}^{2}}/k{{g}^{2}}} \right)$

Topic: Gravitational Force Calculation

Gravitational force: $ \displaystyle 8.34\times {{10}^{{-9}}}N$

Gravitational force: $ \displaystyle 4.17\times {{10}^{{-8}}}N$

Gravitational force: $ \displaystyle 1.67\times {{10}^{{-9}}}N$

Gravitational force: $ \displaystyle 1.67\times {{10}^{{-10}}}N$

None

If a person weighs 600 N on Earth, what would be their weight on Mars where the acceleration due to gravity is $ \displaystyle 3.7m/{{s}^{2}}$ ?

Topic: Weight on Different Planets

Weight: 111 N

Weight: 222 N

Weight: 333 N

Weight: 444 N

None

Which force keeps a satellite in orbit around the Earth?

Topic: Gravity and Orbits

Centripetal force

Centrifugal force

Frictional force

Tension force

None

An object is dropped from a height. Assuming no air resistance, what will be its velocity after 3 seconds? $ \displaystyle \left( {Use g=9.8m/{{s}^{2}}} \right)$

Topic: Free Fall

Velocity: 19.6 m/s

Velocity: 29.4 m/s

Velocity: 39.2 m/s

Velocity: 49.0 m/s

None

What is the gravitational potential energy of a 2 kg mass at a height of 5 meters above the ground?

Topic: Gravitational Potential Energy

Potential energy: 49 J

Potential energy: 98 J

Potential energy: 147 J

Potential energy: 196 J

None

If the distance between two masses is reduced to one-third, how does the gravitational force between them change?

Topic: Inverse Square Law

It becomes nine times

It becomes three times

It becomes one-third

It becomes one-ninth

None

How does the value of g change with increasing altitude?

Topic: Variation of g

It increases

It decreases

It remains constant

It first increases then decreases

None

What is the escape velocity from the surface of the Earth?

Topic: Escape Velocity

7.9 km/s

11.2 km/s

13.6 km/s

15.0 km/s

None

According to Kepler's third law, the square of the orbital period of a planet is proportional to the cube of its:

Topic: Kepler's Laws

Average distance from the Sun

Mass

Radius

Orbital speed

None

10.

What is the gravitational field strength at the surface of the Earth?

Topic: Gravitational Field Strength

$ \displaystyle 9.8N/kg$

$ \displaystyle 9.8m/{{s}^{2}}$

$ \displaystyle 6.67N/kg$

$ \displaystyle 6.67m/{{s}^{2}}$

None

11.

Calculate the gravitational potential energy of a 10 kg object placed 10 meters above the ground. $ \displaystyle (\text{Use }g=9.8m/{{s}^{2}})$

Topic: Gravitational Potential Energy

490 J

980 J

1960 J

3920 J

None

12.

A geostationary satellite orbits the Earth at an altitude of approximately:

Topic: Satellites

36,000 km

42,000 km

48,000 km

54,000 km

None

13.

In a uniform gravitational field, the centre of mass of a body coincides with its:

Topic: Centre of Mass and Centre of Gravity

Centre of gravity

Centre of buoyancy

Centre of pressure

Geometric center

None

14.

According to Newton's Law of Gravitation, if the mass of one object is tripled, the gravitational force between two objects will:

Topic: Newton's Law of Gravitation

Remain the same

Triple

Reduce to one-third

Increase nine times

None

15.

If a person weighs 600 N on Earth, what would be their weight on Jupiter where the acceleration due to gravity is $ \displaystyle 24.8m/{{s}^{2}}$ ?

Topic: Weight on Different Celestial Bodies

1500 N

1200 N

2400 N

3000 N

None

16.

Calculate the orbital speed of a satellite orbiting the Earth at an altitude of 200 km. $ \displaystyle \left( {\text{Radius of Earth R}=6400 km, g=9.8 m/{{s}^{2}}} \right)$

Topic: Orbital Speed Calculation

7.9 km/s

8.4 km/s

9.2 km/s

10.1 km/s

None

17.

Which of the following statements correctly differentiates between mass and weight?

Topic: Mass and Weight

Mass is a force; weight is a measure of inertia

Mass varies with location; weight is constant

Mass is constant; weight varies with location

Mass is measured in newtons; weight is measured in kilograms

None

18.

The gravitational force between two masses is:

Topic: Gravitational Force Direction

Repulsive

Attractive

Both repulsive and attractive

Neither repulsive nor attractive

None

19.

How far will an object fall in 4 seconds if it is dropped from rest? $ \displaystyle (Use g=9.8m/{{s}^{2}})$

Topic: Free Fall Distance

78.4 meters

39.2 meters

19.6 meters

9.8 meters

None

20.

Tides in the oceans are primarily caused by:

Topic: Gravitation and Tides

The rotation of the Earth

The gravitational pull of the Moon and the Sun

The wind and weather patterns

The Earth's magnetic field

None

21.

The components of the gravitational force that affect the orbits of planets are:

Topic: Gravitational Force Components

Radial and tangential

Radial and centrifugal

Centrifugal and centripetal

Tangential and centrifugal

None

22.

When an object is raised to a higher altitude, its gravitational potential energy:

Topic: Gravitational Energy Change

Decreases

Increases

Remains the same

First decreases then increases

None

23.

If a person has a mass of 70 kg, what would be their weight on the Moon where $ \displaystyle g=1.6m/{{s}^{2}}$?

Topic: Weight Calculation on Moon

112 N

70 N

44.8 N

35 N

None

24.

The significance of the gravitational constant G in the Universal Law of Gravitation is that it:

Topic: Gravitational Constant Significance

Determines the strength of the gravitational force

Is the same as the acceleration due to gravity

Varies with location

Is only applicable to objects on Earth

None

25.

Calculate the orbital period of a satellite orbiting the Earth at an altitude where the orbital speed is 7.8 km/s. (Radius of Earth R=6400 km)

Topic: Orbital Period Calculation

1.5 hours

2.0 hours

2.5 hours

3.0 hours

None

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Class 9 - Practice Level 2 – Gravitation Set 1

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