Class 9 Science — Chapter 9: GRAVITATION

What you'll learn

• ▸Centripetal Force and Gravitation
• ▸Universal Law of Gravitation
• ▸The Gravitational Constant (G)
• ▸Calculating Gravitational Force
• ▸Importance of the Universal Law
• ▸Free Fall
• ▸Acceleration Due to Gravity (g)
• ▸Variation in the Value of g

Chapter Summary

--- PAGE 1 --- 0964CH10 Chapter 9 GRAVITATION We have learnt about the motion of objects and force as the cause of motion. We have learnt that a force is needed to change the speed or the direction of motion of an object. We always observe that an object dropped from a height falls towards the earth. We know that all the planets go around the Sun. The moon goes around the earth. In all these cases, there must be some force acting on the objects, the planets and on the moon. Isaac Newton could grasp that the same force is responsible for all these. This force is called the gravitational force. In this chapter we shall learn about gravitation and the universal law of gravitation. We shall discuss the motion of objects under the influence of gravitational force on the earth. We shall study how the weight of a body varies from place to place. We shall also discuss the conditions for objects to float in liquids. 9.1 Gravitation We know that the moon goes around the earth. An object …

Practice Questions from this Chapter

Tap "Get Solution" on any question to ask our AI tutor.

1. Explain how gravity keeps planets orbiting. Get Solution →
2. Describe what causes Earth's ocean tides. Get Solution →
3. Compare gravity on Earth versus the Moon. Get Solution →
4. Who is credited with grasping that the same force responsible for a falling apple also keeps the moon in orbit around the Earth? Get Solution →
5. What is the force that causes acceleration and keeps a body moving along a circular path, acting towards the center? Get Solution →
6. According to the Universal Law of Gravitation, the force between two objects is inversely proportional to what? Get Solution →
7. What does the symbol 'G' represent in the equation F = G(M×m)/d²? Get Solution →
8. Who experimentally determined the value of the universal gravitation constant, G? Get Solution →

Did you know?

• 💡 Your weight on Mars would be about one-third of your weight on Earth.
• 💡 Gravity is so powerful near a black hole that not even light can escape its pull.
• 💡 Astronauts on the International Space Station continuously fall around Earth, creating weightlessness.
• 💡 Earth's gravity is slightly weaker at the equator because the planet bulges there.
• 💡 Gravitational waves are ripples in spacetime, recently detected from colliding black holes.

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