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Chapter Analysis
Intermediate13 pages • EnglishQuick Summary
The chapter on gravitation explains the universal law of gravitation, illustrating how every object in the universe attracts every other object with a force. It covers concepts such as the motion of objects under the influence of gravitational force and how weight varies from place to place. Additionally, it delves into the conditions required for objects to float in liquids, supported by Archimedes' principle. The text uses examples and problems to provide a deeper understanding of gravitation and related phenomena.
Key Topics
- •Universal law of gravitation
- •Weight variation and calculation
- •Motion of celestial bodies
- •Floating and sinking principles
- •Effects of gravity on Earth
- •Centripetal force
- •Applications of Archimedes' principle
Learning Objectives
- ✓Understand the universal law of gravitation and its significance.
- ✓Calculate weight and gravitational forces in different scenarios.
- ✓Explain the motion of objects influenced by gravitational force.
- ✓Determine conditions under which objects float or sink.
- ✓Describe the effect of location on gravitational acceleration.
- ✓Apply Archimedes' principle to practical situations.
Questions in Chapter
State the universal law of gravitation.
Page 102
Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.
Page 102
What do you mean by free fall?
Page 105
What do you mean by acceleration due to gravity?
Page 105
What are the differences between the mass of an object and its weight?
Page 112
Why is the weight of an object on the moon 1/6th its weight on the earth?
Page 112
Additional Practice Questions
What happens to the gravitational force between two objects if the distance between them is halved?
mediumAnswer: The gravitational force increases by a factor of four when the distance is halved, as the force is inversely proportional to the square of the distance between the objects.
Explain how the weight of an object varies based on its location on Earth.
mediumAnswer: The weight of an object varies with location due to changes in gravitational acceleration, which is affected by altitude and the Earth's shape. The weight is greater at the poles than at the equator.
Why does the moon not crash into the Earth despite being attracted by its gravity?
mediumAnswer: The moon is in a stable orbit around the Earth. Its tangential velocity ensures that as it falls towards the Earth due to gravity, it also moves tangentially fast enough to avoid collision, maintaining an orbit.
What factors determine whether an object will float or sink in a liquid?
easyAnswer: An object will float if its density is less than the density of the liquid it is placed in. If its density is greater, it will sink.
Calculate the gravitational force between two objects of 10 kg and 5 kg placed 2 meters apart. (Use G = 6.7 x 10^-11 N m²/kg².)
hardAnswer: Using F = G * (m1 * m2) / r², we get F = (6.7 x 10^-11) * (10 * 5) / 2² = 8.375 x 10^-11 N.
NCERT Exemplar
AvailablePractice with NCERT Exemplar problems and solutions for this chapter. Exemplar problems are designed to help you master the concepts with advanced-level questions.
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