# Moon is Falling

## Trending Questions

**Q.**

At what distance from the earth, on the line between earth and moon, an object will not feel gravity? Assume earth and moon as point masses and no other force by any other body. Earth=6*10^24kg

Moon=7.2*10^22kg

Distance=384000

**Q.**The centripetal acceleration of the moon is because of the gravitational force exerted on the moon by the earth.

- True
- False

**Q.**Earth attracts moon. Why does it not collapse into the Earth?

- Speed of the moon is just enough for it to revolve at the height.
- The sun's gravitational force on the moon is greater than that of Earth.
- The mass of the moon is less than that of Earth.
- The moon is falling at a slow rate and we cannot feel the difference.

**Q.**

Calculate the force by which Earth is attracted by the Sun. Also, find the acceleration and speed of the Earth around the sun. Assume orbit to be circular. Data given, Mass of the Earth:6 x 1024 kg Mass of the Sun:2 x 1030 kg Average distance between Earth and Sun: 150 million km

**Q.**

What is an example of Keplers third law

**Q.**A satellite is revolving around the Earth in a well-defined circular orbit. Comment on the motion of the satellite if the Earth’s gravitational force suddenly becomes zero.

- The satellite continues to move in its circular orbit.
- The satellite starts moving tangentially.
- The satellite comes to rest.
- The satellite falls towards the center of the Earth.

**Q.**

The value of g on the moon is g = GM/R2 where

M is the mass of the moon, R is the radius of the moon

M is the mass of the earth, R is the radius of the earth

M is the mass of the moon, R is the radius of the earth

M is the mass of the earth, R is the radius of the moon

**Q.**

The value of g on the moon is g = GM/R^{2} where

M is the mass of the earth, R is the radius of the earth

M is the mass of the moon, R is the radius of the earth

M is the mass of the earth, R is the radius of the moon

M is the mass of the moon, R is the radius of the moon

**Q.**Since the Moon has a force of gravity which is 6 times lesser than Earth's, why doesn't it collapse into the Earth?

- Due to centripetal force which is the force of gravity exerted by the Earth on Moon.
- The Sun's gravitational force is greater than that of the Earth.
- The mass of the Moon is less than that of the Earth.
- The absence of gravity in space.

**Q.**Since the Moon has a force of gravity which is 6 times lesser than Earth's, why doesn't it collapse into the Earth?

- The absence of gravity in space.
- The mass of the Moon is less than that of the Earth.
- The Sun's gravitational force is greater than that of the Earth.
- Due to centripetal force which is the force of gravity exerted by the Earth on Moon.

**Q.**

How did Galileo prove that different bodies fall towards the earth at the same rate?

**Q.**Moon attracts Earth due to gravity.

- True
- False

**Q.**Moon would continue to orbit about Earth without gravity.

- True
- False

**Q.**

- Earthquakes
- Tides
- Volcanoes

**Q.**Since the Moon has a force of gravity which is 6 times lesser than Earth's, why doesn't it collapse into the Earth?

- Due to centripetal force which is the force of gravity exerted by the Earth on Moon.
- The Sun's gravitational force is greater than that of the Earth.
- The mass of the Moon is less than that of the Earth.
- The absence of gravity in space.

**Q.**The following figure shows the elliptical path of a planet about the Sun. The two shaded parts, S1 and S2, have equal areas. If t1 and t2 be the time taken by the planet to go from A to B and from C to D respectively, then:

- t1>t2
- t1<t2
- t1=t2
- t1 and t2 cannot be compared.

**Q.**The orbit of a planet around the Sun is _____ in shape.

- elliptical
- circular
- triangular
- parabolic

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

- 25.1 days.
- 20.2 days.
- 33.5 days.
- 27.3 days.

**Q.**Which of the following are correct about Kepler's law?

- The path of the planets around the sun is elliptical, with the sun being located at one of the two foci.

- The line joining the planet and the sun sweeps equal areas in equal intervals of time.

- The cube of the average distance of a planet from the sun is directly proportional to the square of the planet's orbital time period.

- The path of the planets around the sun is circular, with the sun being located at its centre.

**Q.**

What should be the angular speed of earth so that body lying on equator may appear weightlessness

(g=10m/s , R=6400 km)

1) 1/800 rad/s

2) 1/400 rad/s

3) 1/600 rad/s

4) 1/100 rad/s

**Q.**Since the Moon has a force of gravity which is 6 times lesser than Earth's, why doesn't it collapse into the Earth?

- Due to centripetal force which is the force of gravity exerted by the Earth on Moon.
- The mass of the Moon is less than that of the Earth.
- The Sun's gravitational force is greater than that of the Earth.
- The absence of gravity in space.

**Q.**

a satellite is revolving around the earth at a height of 600 km from the surface. find the speed of the satellite , its magnitude of acceleration and time period of its motion around the earth. (take Mass of earth = 6 x 10^24 kg) and ( radius of earth = 6400 km)