Moon's Revolution around Earth

Q.

How do day and night occur on the earth?

Q.

Gravitational force acts on all objects in proportion to their masses. Why then does a heavy object not fall faster than a light object?

Q.

Calculate the force of gravitation between the earth and the sun, given that the mass of the earth = 6×10²⁴kg and of the sun = 2×10³⁰kg. The average distance between the two is 1.5×10¹¹m.

Q.

Which force is responsible for the moon revolving round the earth ?

Q.

Suppose the gravity of the earth suddenly becomes zero, then in which direction will the moon begin to move if no other celestial body affects it?

Q. How many days are required by moon to complete one revolution around the earth?

1. $20.2$ days.
2. $25.1$ days.
3. $27.3$ days.
4. $33.5$ days.

Q.

Calculate the gravitational force between 2 stars having mass ${10}^{25}kg$ and $5\times {10}^{30}kg$ respectively. Distance between them is $2\times {10}^{10}m$.

Q.

Earth is considered to have its mass concentrated at its point centre then why does acc^{​​​​n}​​​ due to gravity decrease while we go deeper inside the earth?

Q. If the medium between Earth and its moon was made 10 times denser, then the gravitational force between the two would increase 10 times.

1. False
2. True

Q. If a bomb blast on the moon. Its sound will be heard on earth after how much time?

1. 1800 minutes
2. 3.8 minutes
3. 2600 minutes
4. Never be heard

Q. Question 10
The atmosphere is held to the earth by

(a) gravity
(b) wind
(c) clouds
(d) earth’s magnetic field

Q.

Does moon also revolves in elliptical orbit

Q. The atmosphere is bound to the Earth due to.

1. clouds
2. wind
3. gravity
4. magnetic field

Q.

A man covers $60m$ distance in one minute on the surface of the earth. What is the distance he will cover on the surface of the moon in one minute? $\left(g_m=\frac{g_e}{6}\right)$

1. $6m$

2. $60m$

3. $\frac{60}{6}m$

4. $\sqrt{60}m$

Q. are caused on Earth due to the gravitational pull of the Moon.

1. Earthquakes
2. Tides
3. Volcanoes

Q. The mass of sun 2×10³⁰ kg and mass of earth is 6×10²⁴ kg . If the distance between is 1.5 × 10⁸ km . Calculate the force of gravitation between. (G = 6.7 × 10^-11)

Q.

The separation between the masses is tripled. How is the magnitude of gravitational force between them affected? How?

Q.

When Neil Armstrong and Edwin Aldrin landed on moon, they could see each other but could not listen each other without a radio. This is because

1. their ear drums were not working on moon.

2. light and radio waves can travel through vacuum but not the sound wave.

3. they were compelled to use radios to record their conversation.

4. there was no material medium to transport sound

Q. How many days are required by moon to complete one revolution around the earth?

1. $20.2$ days.
2. $25.1$ days.
3. $27.3$ days.
4. $33.5$ days.

Q.

How do we use gravitational energy in daily life?

Q. Gravitational force does not exist between the Moon and a person standing on its surface.

1. False
2. True

Q.

Sams father and mother are astronauts. Last month they returned from a tour to the moon. Sams father told him that they had an air-filled helmet and it also had a microphone, which they used for talking to each other. But his mother was not able to listen to him when they opened their helmets. (Assume they were wearing oxygen masks when they opened their helmets). What is the reason?

Q. What happens to gravitational force when the masses of two object are tripled and the distance between rhem are also tripled

Q. If a bomb blast on the moon. Its sound will be heard on earth after how much time?

1. 1800 minutes
2. Never be heard
3. 3.8 minutes
4. 2600 minutes

Q. Gravitational force does not exist between the Moon and a person standing on its surface.

1. False
2. True

Q. Karim was travelling from Mars to Earth. Determine the distance from Mars at which the gravitational forces on spaceship by Earth and Mars will be equal. Take mass of earth as 10 times the mass of Mars. Distance between Mars and Earth is 230 million km.

Q. This section contains 1 Assertion-Reason type question, which has 4 choices (a), (b), (c) and (d) out of which ONLY ONE is correct.
इस खण्ड में 1 कथन-कारण प्रकार का प्रश्न है, जिसमें 4 विकल्प (a), (b), (c) तथा (d) दिये गये हैं, जिनमें से केवल एक सही है।

A : The line joining the planet to the sun sweeps out equal area in equal intervals of time.
A : ग्रह से सूर्य को जोड़ने वाली रेखा समान समयान्तराल में समान क्षेत्रफल घेरती है।

R : The gravitational force between two bodies increases with increase in mass of either of the body.
R : दो पिण्डों के मध्य गुरुत्वाकर्षण बल, किसी भी पिण्ड के द्रव्यमान में वृद्धि करने पर बढ़ता है।

1. Both (A) and (R) are true and (R) is the correct explanation of (A)
   
   (A) तथा (R) दोनों सही हैं तथा (R), (A) का सही स्पष्टीकरण है
2. Both (A) and (R) are true but (R) is not the correct explanation of (A)
   
   (A) तथा (R) दोनों सही हैं लेकिन (R), (A) का सही स्पष्टीकरण नहीं है
3. (A) is true but (R) is false
   
   (A) सही है लेकिन (R) गलत है
4. (A) is false but (R) is true
   
   (A) गलत है लेकिन (R) सही है

Q. Reverberation of sound is due to

1. multiple refractions
2. multiple reflections
3. multiple diffractions
4. multiple polarization

Q. If the medium between the Earth and its moon was made 10 times denser, then the gravitational force between the two would

1. increase
2. decrease
3. remains same

Q. Which of the following figures represents the uniform motion of a moving object correctly?

1. 
2. 
3. 
4.