Chapter 10
Gravitation
Exercises
1. How does the force of gravitation between two objects change when the distance between them is reduced to half?
āϝেāϤিāϝ়া āϏেāĻāĻŦোā§°ā§° āĻŽাāĻā§° āĻĻূā§°āϤ্āĻŦ āĻāϧাāϞৈ āĻš্ā§°াāϏ āĻšāϝ় āϤেāϤিāϝ়া āĻĻুāĻা āĻŦāϏ্āϤুā§° āĻŽাāĻā§° āĻŽাāϧ্āϝাāĻā§°্āώāĻŖāĻļāĻ্āϤি āĻেāύেāĻĻā§°ে āϏāϞāύি āĻšāϝ়?
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2. Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?
āĻŽাāϧ্āϝাāĻā§°্āώāĻŖāĻļāĻ্āϤিāϝ়ে āϏāĻāϞো āĻŦāϏ্āϤুā§° āĻāĻĒā§°āϤ āϤেāĻঁāϞোāĻā§° āĻā§°ā§° āĻ āύুāĻĒাāϤāϤ āĻাāĻŽ āĻā§°ে। āϤেāύেāĻš'āϞে, āĻāĻা āĻāϧুā§° āĻŦāϏ্āϤু āĻĒাāϤāϞ āĻŦāϏ্āϤুāϤāĻৈ āĻĻ্ā§°ুāϤāĻāϤিāϤ āύāĻĒā§°ে?
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3. What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (Mass of the earth is 6 x 1024 kg and radius of the earth is 6.4 x 106 m.)
āĻĒৃāĻĨিā§ąী āĻā§°ু āĻāϝ়াā§° āĻĒৃāώ্āĻ āϤ 1 āĻিāϞোāĻ্ā§°াāĻŽ āĻŦāϏ্āϤুā§° āĻŽাāĻā§° āĻŽাāϧ্āϝাāĻā§°্āώāĻŖ āĻļāĻ্āϤিā§° āĻĒā§°িāĻŽাāĻŖ āĻিāĻŽাāύ? (āĻĒৃāĻĨিā§ąীā§° āĻā§° āĻšৈāĻে 6 āĻĻāĻļāĻ 1024 āĻিāĻ্ā§°া āĻā§°ু āĻĒৃāĻĨিā§ąীā§° āĻŦ্āϝাāϏাā§°্āϧ 6.4 āĻĻāĻļāĻ 106 āĻŽি.)
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4. The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with a force that is greater or smaller or the same as the force with which the moon attracts the earth? Why?
āĻĒৃāĻĨিā§ąী āĻā§°ু āĻāύ্āĻĻ্ā§° āĻŽāĻšাāĻā§°্āώāĻŖāĻļāĻ্āϤিā§° āĻĻ্āĻŦাā§°া āĻāĻāύে āϏিāĻāύ⧰ āĻĒ্ā§°āϤি āĻāĻā§°্āώিāϤ āĻšāϝ়। āĻĒৃāĻĨিā§ąীāϝ়ে āĻāύ্āĻĻ্ā§°āĻ āĻāύে āĻāĻ āĻļāĻ্āϤিā§°ে āĻāĻā§°্āώিāϤ āĻā§°ে āύেāĻি āϝিāĻো āĻĄাāĻā§° āĻŦা āϏ⧰ু āĻŦা āĻāύ্āĻĻ্ā§°āĻ āĻĒৃāĻĨিā§ąীāĻ āĻāĻā§°্āώিāϤ āĻā§°া āĻļāĻ্āϤিā§° āĻĻā§°ে āĻāĻে? āĻিāϝ়?
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5. If the moon attracts the earth, why does the earth not move towards the moon?
āϝāĻĻি āĻāύ্āĻĻ্ā§°āĻ āĻĒৃāĻĨিā§ąীāĻ āĻāĻā§°্āώিāϤ āĻā§°ে, āĻĒৃāĻĨিā§ąী āĻāύ āĻāύ্āĻĻ্ā§°ā§° āĻĢাāϞে āĻিāϝ় āύাāϝাāϝ়?
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6. What happens to the force between two objects, if (i) the mass of one object is doubled? (ii) the distance between the objects is doubled and tripled? (iii) the masses of both objects are doubled?
āϝāĻĻি (āĻāĻ) āĻāĻা āĻŦāϏ্āϤুā§° āĻā§° āĻĻুāĻুāĻŖ āĻšāϝ়, āϤেāύ্āϤে āĻĻুāĻা āĻŦāϏ্āϤুā§° āĻŽাāĻā§° āĻŦāϞ⧰ āĻি āĻš'āĻŦ? (āĻāĻāĻāĻ) āĻŦāϏ্āϤুāĻŦোā§°ā§° āĻŽাāĻā§° āĻĻূā§°āϤ্āĻŦ āĻĻুāĻুāĻŖ āĻā§°ু āϤিāύিāĻুāĻŖ āĻā§°া āĻšāϝ়? (āϤৃāϤীāϝ়) āĻĻুāϝ়োāĻা āĻŦāϏ্āϤুā§° āĻā§° āĻĻুāĻুāĻŖ āĻā§°া āĻšāϝ়?
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7. What is the importance of universal law of gravitation?
āĻŽāĻšাāĻā§°্āώāĻŖā§° āϏাā§°্āĻŦāĻāύীāύ āύিāϝ়āĻŽā§° āĻুā§°ুāϤ্āĻŦ āĻি?
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8. What is the acceleration of free fall?
āĻŽুāĻ্āϤ āĻĒāϤāύ⧰ āϤ্āĻŦā§°āĻŖ āĻি?
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9. What do we call the gravitational force between the earth and an object?
āĻāĻŽি āĻĒৃāĻĨিā§ąী āĻā§°ু āĻŦāϏ্āϤুāĻāĻাā§° āĻŽাāĻā§° āĻŽাāϧ্āϝাāĻā§°্āώāĻŖ āĻļāĻ্āϤিāĻ āĻি āĻŦুāϞি āĻāĻঁ?
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10. Amit buys few grams of gold at the poles as per the instruction of one of his friends. He hands over the same when he meets him at the equator. Will the friend agree with the weight of gold bought? If not, why? [Hint: The value of g is greater at the poles than at the equator.] 11. Why will a sheet of paper fall slower than one that is crumpled into a ball?
āĻ āĻŽিāϤে āϤেāĻঁā§° āĻāĻāύ āĻŦāύ্āϧুā§° āύিā§°্āĻĻেāĻļāύা āĻ āύুāϏ⧰ি āĻুāĻাāĻŦোā§°āϤ āĻেāĻāĻ্ā§°াāĻŽ āϏোāĻŖ āĻ্ā§°āϝ় āĻā§°ে। āϝেāϤিāϝ়া āϤেāĻঁ āĻŦিāώুā§ą ā§°েāĻাāϤ āϞāĻ āĻĒাāϝ় āϤেāϤিāϝ়া āϤেāĻঁ āĻāĻেāĻা āĻšāϏ্āϤাāύ্āϤ⧰ āĻā§°ে। āĻŦāύ্āϧুāĻāύে āĻিāύা āϏোāĻŖā§° āĻāĻāύ⧰ āϏৈāϤে āϏāύ্āĻŽāϤ āĻš'āĻŦāύে? āϝāĻĻি āύāĻšāϝ়, āĻিāϝ়? [āĻāĻ্āĻিāϤ: āĻŦিāώুā§ąā§°েāĻাāϤāĻৈ āĻŽেā§°ুāϤ āĻি-ā§° āĻŽূāϞ্āϝ āĻ āϧিāĻ।]
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12. Gravitational force on the surface of the moon is only as strong as gravitational force on the earth. What is the weight in newtons of a 10 kg object on the moon and on the earth?
āĻāύ্āĻĻ্ā§°āĻĒৃāώ্āĻ āϤ āĻŽাāϧ্āϝাāĻā§°্āώāĻŖāĻļāĻ্āϤি āĻেā§ąāϞ āĻĒৃāĻĨিā§ąীā§° āĻŽাāϧ্āϝাāĻā§°্āώāĻŖāĻļāĻ্āϤিā§° āĻĻā§°েāĻļāĻ্āϤিāĻļাāϞী। āĻāύ্āĻĻ্ā§° āĻā§°ু āĻĒৃāĻĨিā§ąীāϤ 10 āĻিāϞোāĻ্ā§°াāĻŽ āĻŦāϏ্āϤুā§° āύিāĻāĻāύ⧰ āĻāĻāύ āĻিāĻŽাāύ?
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13. A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate (i) the maximum height to which it rises, (ii) the total time it takes to return to the surface of the earth.
āĻŦāϞ āĻāĻা 49 āĻŽিāĻাā§°/āĻে āĻŦেāĻā§° āϏৈāϤে āĻāϞāĻŽ্āĻŦāĻাā§ąে āĻāĻĒā§°āϞৈ āĻĻāϞিāϝ়াāĻ āĻĻিāϝ়া āĻšāϝ়। (āĻāĻ) āĻ āϝি āĻāĻ্āĻāϤাāϞৈ āĻāĻ িāĻে āĻāĻŖāύা āĻā§°āĻ, (āĻāĻāĻāĻ) āĻĒৃāĻĨিā§ąীā§° āĻĒৃāώ্āĻ āϞৈ āĻূā§°ি āĻāĻšিāĻŦāϞৈ āϞāĻা āĻŽুāĻ āϏāĻŽāϝ়।
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14. A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity just before touching the ground.
⧧⧝.ā§Ŧ āĻŽিāĻাā§° āĻāĻ্āĻāϤাā§° āĻāĻা āĻাā§ąাā§°ā§° āĻāĻĒā§°ā§° āĻĒā§°া āĻāĻা āĻļিāϞ āĻā§°ি āĻĻিāϝ়া āĻšāϝ়। āĻŽাāĻি āϏ্āĻĒā§°্āĻļ āĻā§°াā§° āĻ িāĻ āĻāĻāϤে āĻāϝ়াā§° āĻ āύ্āϤিāĻŽ āĻŦেāĻ āĻāĻŖāύা āĻā§°āĻ।
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15. A stone is thrown vertically upward with an initial velocity of 40 m/s. Taking g= 10 m/s², find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?
40 āĻŽিāĻাā§°/āĻেāĻেāĻŖ্āĻĄā§° āĻĒ্ā§°াā§°āĻŽ্āĻিāĻ āĻŦেāĻā§° āϏৈāϤে āĻāĻা āĻļিāϞ āĻāϞāĻŽ্āĻŦāĻাā§ąে āĻāĻĒā§°āϞৈ āĻĻāϞিāϝ়াāĻ āĻĻিāϝ়া āĻšāϝ়। āĻ্ā§°াāĻŽ= 10 āĻŽিāĻাā§°/āĻে² āĻ্ā§°āĻšāĻŖ āĻā§°ি, āĻļিāϞāĻোā§° āĻĻ্āĻŦাā§°া āϏ⧰্āĻŦাāϧিāĻ āĻāĻ্āĻāϤা āĻĒ্ā§°াāĻĒ্āϤ āĻā§°āĻ। āĻļিāϞে ā§°ে āĻাāĻĒ āĻাāϝ় āύেāĻ āϏ্āĻĨাāύাāύ্āϤ⧰ āĻā§°ু āĻŽুāĻ āĻĻূā§°āϤ্āĻŦ āĻিāĻŽাāύ?
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16. Calculate the force of gravitation between the earth and the Sun, given that the mass of the earth = 6 x 1024 kg and of the Sun = 2 x 1030 kg. The average distance between the two is 1.5 x 10¹¹ m.
āĻĒৃāĻĨিā§ąী āĻā§°ু āϏূā§°্āϝ⧰ āĻŽাāĻā§° āĻŽāĻšাāĻā§°্āώāĻŖāĻļāĻ্āϤি āĻāĻŖāύা āĻā§°āĻ, āϝিāĻšেāϤু āĻĒৃāĻĨিā§ąীā§° āĻā§° = 6 āĻĻāĻļāĻ 1024 āĻিāĻ্ā§°া āĻā§°ু āϏূā§°্āϝ⧰ = 2 āĻĻāĻļāĻ 1030 āĻিāĻ্ā§°া। āĻĻুāϝ়োāĻাā§° āĻŽাāĻā§° āĻāĻĄ় āĻĻূā§°āϤ্āĻŦ āĻšৈāĻে 1.5 āĻāĻ্āϏ 10¹¹ āĻŽিāĻাā§°।
17. A stone is allowed to fall from the top of a tower 100 m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 m/s. Calculate when and where the two stones will meet.
āĻāĻা āĻļিāϞ 100 āĻŽিāĻাā§° āĻāĻ āĻাā§ąাā§°ā§° āĻāĻĒā§°ā§° āĻĒā§°া āĻĒā§°িāĻŦāϞৈ āĻĻিāϝ়া āĻšāϝ় āĻā§°ু āĻāĻে āϏāĻŽāϝ়āϤে āĻāύ āĻāĻা āĻļিāϞ 25 āĻŽিāĻাā§°/āĻে āĻŦেāĻā§° āϏৈāϤে āĻŽাāĻিā§° āĻĒā§°া āĻāϞāĻŽ্āĻŦāĻাā§ąে āĻāĻĒā§°āϞৈ āĻĒ্ā§°āĻ্āώেāĻĒ āĻā§°া āĻšāϝ়। āĻļিāϞ āĻĻুāĻা āĻেāϤিāϝ়া āĻā§°ু āĻ'āϤ āϞāĻ āĻš'āĻŦ āĻāĻŖāύা āĻā§°āĻ।
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18. A ball thrown up vertically returns to the thrower after 6 s. Find
(a) the velocity with which it was thrown up,
(b) the maximum height it reaches, and
(c) its position after 4 s.
āĻāϞāĻŽ্āĻŦāĻাā§ąে āĻĻāϞিāϝ়াāĻ āĻĻিāϝ়া āĻāĻা āĻŦāϞ ā§Ŧ āĻেāĻেāĻŖ্āĻĄā§° āĻĒিāĻāϤ āĻĨ্ā§°'āϝ়াā§°āϞৈ āĻূā§°ি āĻāĻšে। āĻŦিāĻাā§°
(āĻ) āĻāϝ়াāĻ āϝি āĻŦেāĻেā§°ে āĻĒেāϞাāĻ āĻĻিāϝ়া āĻšৈāĻিāϞ,
(āĻ) āĻ āϏ⧰্āĻŦাāϧিāĻ āĻāĻ্āĻāϤাāϤ āĻāĻĒāύীāϤ āĻšāϝ়, āĻā§°ু
(āĻ) 4 āĻে.-ā§° āĻĒিāĻāϤ āĻāϝ়াā§° āϏ্āĻĨিāϤি।
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19. In what direction does the buoyant force on an object immersed in a liquid act?
āϤ⧰āϞ āĻĒāĻĻাā§°্āĻĨāϤ āύিāĻŽāĻ্āĻিāϤ āĻŦāϏ্āϤু āĻāĻাā§° āĻāĻĒā§°āϤ āĻāĻ্āĻāϞ āĻļāĻ্āϤিāϝ়ে āĻি āĻĻিāĻļāϤ āĻাāĻŽ āĻā§°ে?
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20. Why does a block of plastic released under water come up to the surface of water?
āĻĒাāύীā§° āϤāϞāϤ āĻā§°ি āĻĻিāϝ়া āĻĒ্āϞাāώ্āĻিāĻā§° āĻāĻা āĻāĻŖ্āĻĄ āĻĒাāύীā§° āĻĒৃāώ্āĻ āϞৈ āĻিāϝ় āĻāĻšে?
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21. The volume of 50 g of a substance is 20 cm³. If the density of water is 1 g cm³, will the substance float or sink?
āĻĒāĻĻাā§°্āĻĨ āĻāĻাā§° 50 āĻ্ā§°াāĻŽā§° āĻĒā§°িāĻŽাāĻŖ āĻšৈāĻে 20 āĻেāĻŽি³। āϝāĻĻি āĻĒাāύীā§° āĻāύāϤ্āĻŦ 1 āĻ্ā§°াāĻŽ āĻেāĻŽি³ āĻšāϝ়, āĻĒāĻĻাā§°্āĻĨāĻো āĻাঁāĻšি āĻĨাāĻিāĻŦ āύে āĻĄুāĻŦ āϝাāĻŦ?
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22. The volume of a 500 g sealed packet is 350 cm³. Will the packet float or sink in water if the density of water is 1 g cm 3? What will be the mass of the water displaced by this packet?,
500 āĻ্ā§°াāĻŽ āĻীāϞ āĻā§°া āĻĒেāĻেāĻāĻāĻাā§° āĻāϝ়āϤāύ āĻšৈāĻে 350 āĻেāĻŽি³। āϝāĻĻি āĻĒাāύীā§° āĻāύāϤ্āĻŦ 1 āĻ্ā§°াāĻŽ āĻেāĻŽি 3 āĻšāϝ় āϤেāύ্āϤে āĻĒেāĻেāĻāĻো āĻাঁāĻšি āĻĨাāĻিāĻŦ āύে āĻĒাāύীāϤ āĻĄুāĻŦ āϝাāĻŦ? āĻāĻ āĻĒেāĻেāĻāĻোā§° āĻĻ্āĻŦাā§°া āϏ্āĻĨাāύāĻ্āϝুāϤ āĻšোā§ąা āĻĒাāύীā§° āĻā§° āĻিāĻŽাāύ āĻš'āĻŦ?,
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Question Type By- Parina Hazarika
Post Id: DABP002935