Earth, Moon and High Tide

Q.

Difference between centrifugal and centripetal force

Q. If the moon attracts the earth, why does the earth not move towards the moon?

Q. According to Kepler's third law of orbital periods, average distance $\left(r\right)$ of a planet from the Sun is related to the planet's orbital time period $\left(T\right)$ as:

1. $r\propto T$
2. $r^3\propto T^2$
3. $r^3\propto T$
4. $r\propto T^2$

Q.

A body is orbiting around the earth at a mean radius which is two times as greater as the parking orbit of a satellite, the period of the body in days is

1. $4$

2. $16$

3. $2\sqrt{2}$

4. $64$

Q. During the revolution of a planet around the Sun, the line joining the planet and the Sun sweeps equal areas in equal intervals of time. This law is called:

1. Kepler’s first law of planetary orbits
2. Kepler’s second law of orbital areas
3. Kepler’s third law of orbital periods
4. Galileo's principle of relativity

Q. The force that acts towards the centre, on a body moving in a circular path is called the ______.

1. frictional force
2. centrifugal force
3. centripetal force
4. muscular force

Q.

Derivation of keplers 3rd law without gravitational formula

Q.

Give reasons for the following:

Motion of a stone tied to a thread being swirled around is said to be circulatory.

Q.

What does Keplers 2nd law mean?

Q. Question 5
If the moon attracts the earth, why does the earth not move towards the moon?

Q. State three Kepler's law of planetary motion. [3 MARKS]

Q. When we throw an apple upwards, then it comes back to the ground. But why doesn't the moon come down towards the earth?

Q.

Earth is continuously pulling the moon towards its center. Why does not the moon fall on the earth?

Q.

how gravity in the moonand what is gravitation

Q. The picture shows a bucket being whirled around in an area of no gravity, with a help of a string with a very high speed. Which of the following options approximately depict correct analogy of motion of bucket with that of the moon?

1. Tension in string and Gravitational force on moon are pulling forces.
2. Fixed point of the string and the moon are at their respective focus.
3. Tension on the bucket and gravitational force on the moon provides centripetal force.
4. All of the above.

Q. What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (Mass of the earth is $6\times {10}^{24}kg$ and radius of the earth is $6.4\times {10}^{6}m$)

Q. The time periods and the mean radii of the orbits of two planets around Sun are $T_1,T_{2}and{r}_1,r_2$ respectively. The ratio $\frac{T_1}{T_2}$ is equal to:

1. $(\frac{r_1}{r_2}{)}^{\frac{3}{2}}$
2. $(\frac{r_2}{r_1}{)}^{\frac{3}{2}}$
3. $(\frac{r_1}{r_2}{)}^{\frac{1}{2}}$
4. $(\frac{r_2}{r_1}{)}^{\frac{1}{2}}$

Q. The moon orbit around the earth due to gravitational force of the earth.why does not earth orbit around the moon, when moon also exerts equal and oppossite force towards the earth

Q. The Moon rotates around Earth due to the presence of ______ between them.

1. magnetic force
2. gravitational force
3. electric force
4. frictional force

Q. As per Kepler's laws, the path of planets around the Sun is:

1. Circular
2. Elliptical
3. Rectangular
4. Triangular

Q. Without the Earth's gravitational force, the Moon would:

1. Keep rotating around the Earth.
2. Fly away from the Earth.
3. Fall onto the Earth.
4. Become stationary.

Q. If the moon attracts the earth, why does the earth not move towards the moon?

Q. Question 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 $6\times {10}^{24}kg$ and radius of the earth is $6.4\times {10}^{6}m$)

Q.

If suns gravitation is more than earth.so why doesn't the moon revolve around the sun

Q. When a body is moving along a circular track, the force directed towards the centre of the track is called

1. centripetal force
2. centrifugal force
3. gravitational force

Q. If the medium between the Earth and the Moon becomes 10 times denser, then the gravitational force between the two would increase 10 times.

1. True
2. False

Q. How is force defined?

Q.

According to Kepler’s III law of planetary motion, __________ . (T = time period, R = Radius of the orbit)

1. $T\alpha R$

2. $T^2\alpha R^3$

3. $T^3\alpha R^2$

4. $T^{}\alpha R^3$

Q.

is kepler law important?

Q. In which direction will the moon move, if the gravitational pull of the earth suddenly becomes zero?