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Gravitation
6 Class 9 Physics questions with answers and explanations.
Printable worksheet with answer key
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Newton's law of gravitation says the force between two masses is proportional to:
- 1 The sum of the masses
- 2 The difference of the masses
- 3 The distance between them
- 4 The product of the masses
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Correct answer: The product of the masses
F = G m1 m2 / d2, so the force is proportional to the product of the masses.
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If the distance between two masses is doubled, the gravitational force becomes:
- 1 Four times
- 2 One quarter
- 3 Half
- 4 Double
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Correct answer: One quarter
F is proportional to 1 / d2. Doubling d makes the force one quarter.
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The value of g near the surface of the Earth is about:
- 1 0.98 m/s2
- 2 98 m/s2
- 3 9.8 m/s2
- 4 6.67 m/s2
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Correct answer: 9.8 m/s2
The acceleration due to gravity near Earth's surface is about 9.8 m/s2.
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The acceleration due to gravity on the Moon compared with Earth is about:
- 1 Six times greater
- 2 Zero
- 3 One sixth
- 4 The same
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Correct answer: One sixth
The Moon has less mass, so g there is about one sixth of the value on Earth.
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A satellite stays in orbit around the Earth because:
- 1 It is very light
- 2 It has no weight
- 3 Gravity provides the centripetal force
- 4 There is no gravity in space
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Correct answer: Gravity provides the centripetal force
Gravity pulls the satellite towards the Earth and acts as the centripetal force that keeps it on a curved path.
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The mass of a body on the Moon compared with its mass on Earth is:
- 1 More
- 2 The same
- 3 Less
- 4 Zero
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Correct answer: The same
Mass is the amount of matter and does not change with place. Only weight changes.