What is gravity?

State the Newton's universal law of gravitation.

Write the nature of gravitational force.

Define gravitational constant (G).

Under what conditions is the value of gravitational force equal to gravitational constant (F=G)?

Write two effects of gravitational force.

Mathematically present the difference in the gravitational force between two objects when the mass of each is made double and the distance between them is made on fourth of their initial distance.

What is gravitational force?

What is free fall? Give two examples of it.

Under what conditions is an object said to be in free fall?

Write the conclusions of the feather and coin experiment.

What is weightlessness?

Mention any four effects of gravitational force.

Prove that acceleration due to the gravity of the Earth is inversely proportional to the square of its radius $\rm \left ( g \propto \frac{1}{R^2} \right )$.

Mention the factors that influence acceleration due to gravity.

The acceleration due to the gravity on the Earth's surface is 9.8 ms^-2. What does this mean?

The mass of the Moon is about 1/81 times the mass of the Earth and its radius is about 37/10 times the radius of the Earth. If the earth is squeezed to the size of the moon, what will be the effect on its acceleration due to gravity? Explain with the help of mathematical calculation.

The acceleration due to gravity of an object of mass 1 kg in outer space is 2m/s². What is the acceleration due to gravity of another object of mass 10 kg at the same point? Justify with arguments.

A man first measures the mass and weight of an object in the mountain and then in the Terai. Compare the data that he obtains.

A student suggests a trick for gaining profit in a business. He suggests buying organes from the mountain and selling them to Terai at the cost price. If a beam balance is used during this transaction, explain, based on scientific fact, whether his trick goes wrong or right.

How is it possible to have a safe landing while jumping from a flying airplane using a parachute? Is it possible to have a safe landing on the moon in the same way? Explain with reasons.

The acceleration of an object moving on the earth is inversely proportional to the mass of the object, but for an object falling towards the surface of the earth, the acceleration does not depend on the mass of the object, why?

What is the relation between the distance between two objects (d) and the gravitational force (F) produced between them?

What is the change in the gravitational force between two objects when their mass is doubled?

If the gravitational force between two objects on Earth is 60 N, what is the gravitational force between those two objects on the moon?

Which one of the following statements is correct?

At which of the following places do you weigh the most?

The radius of the Earth is 6371 km and the weight of an object on the Earth is 800 N. What is the weight of the object at a height of 6371 km from the surface of the earth?

If the mass and the radius of a celestial body are two times the mass and the radius of the earth respectively, what is the value of acceleration due to the gravity of that body?

What will be the weight of a man on the moon if his weight on the Earth is 750 N? (The acceleration due to the gravity of the moon = 1.63  $\rm ms^{-2}$)

The mass of a planet B is twice the mass of planet A but its radius is half of the radius of planet A. Similarly, the mass of planet C is half of the mass of planet A, but its radius is twice the radius of planet A. If the weight of an object in planets A, B, and C is W1, W2, and W3, respectively, which of the following order is correct? 

Which one of the following conclusions is correct while observing a freely falling object every second?

Differentiate: Gravitational constant G and acceleration due to gravity

Differentiate: mass and weight

Acceleration due to gravity is not the same in all parts of the earth.

Jumping from a significant height may cause more injury.

Mass of Jupiter is about 319 times the mass of the Earth, but its acceleration due to gravity is only about 2.6 times the acceleration due to gravity of the Earth. Why?

Among the objects dropped from the same height in the polar region and the equatorial region of the earth, the object dropped in the polar region falls faster. Why?

Out of the two paper sheets, one is folded to form a ball. If the paper ball and the sheet of paper are dropped simultaneously in the air, the folded paper will fall faster. Why?

When a marble and a feather are dropped simultaneously in a vacuum, they reach the ground together (at the same time). Why?

As you climb Mount Everest, the weight of the goods that you carry decreases. Give reason.

It is difficult to lift a big stone on the surface of the earth, but it is easy to lift a smaller one. Why?

Mass of an object remains constant but its weight varies from place to place. Give reason.

One will have an eerie feeling when he/she moves down while playing a Rote Ping. Why?

What is gravity?

Write the nature of gravitational force.

The masses of objects A and B are 20 kg and 40 kg respectively. If the distance between their centers is 5 m, calculate the gravitational force produced between them.

Mass of the Sun and Jupiter are $\rm 2 \times 10^{30}$ and $\rm 1.9 \times 10^{27}$ kg respectively. If the distance between Sun and Jupiter is $\rm 1.8 \times 10^{8}$ km, calculate the gravitational force between Sun and Jupiter.

The Gravitational force produced between the Earth and the Moon is $\rm 2.01 \times 10^{20}$ N. If the distance between these two masses is $\rm 3.84 \times 10^{5}$ km and the mass of the earth is $\rm 5.972 \times 10^{24}$ kg, calculate the mass of the moon.

The mass of the moon is $\rm 7.342 \times 10^{22}$ kg. If the average distance between the earth and the moon is 384400 km, calculate the gravitational force exerted by the moon on every kilogram of water on the surface of the earth.

If the mass of the moon is $\rm 7.342 \times 10^{22}$ kg and its radius is 1737 km, calculate its acceleration due to gravity.

Mass of the Earth is $\rm 5.972 \times 10^{24}$ kg and the diameter of the moon is 3474 km. If the earth is compressed to the size of the moon, how many times will be the change in acceleration due to gravity of the earth so formed than that of the real Earth?

If the mass of Mars is $\rm 6.4 \times 10^{23}$ and its radius is 3389 km, calculate its acceleration due to gravity. What is the weight of an object of mass 200 kg on the surface of Mars?

The acceleration due to the gravity of the earth is $\rm 9.8 ms^{-2}$. If the mass of Jupiter is 319 times the mass of the Earth and its radius is 11 times the radius of the Earth, calculate the acceleration due to the gravity of Jupiter. What is the weight of an object of mass 100 kg on Jupiter?

The Gravitational force produced between the Earth and the Sun is $\rm 3.54 \times 10^{22}$ N. If the masses of the Earth and the Sun are $\rm 5.972 \times 10^{24}$ kg and $\rm 2 \times 10^{30}$ kg respectively, what is the distance between them?

The Earth's mass is $\rm 5.972 \times 10^{24}$ kg and its radius is 6371 km. If the height of Mt. Everest is 8848.86 m from the sea level, calculate the weight of an object of mass 10 kg at the peak of Mt. Everest.

The acceleration due to gravity of the Mars is $\rm 3.75 ms^{-2}$. How much mass can a weight-lifter lift on Mars who can lift 100 kg mass on the Earth?

If a stone is dropped from a height of 15 m, how long will it take to reach the ground? Calculate the velocity of the stone when it hits the ground.

If a cricket ball is thrown vertically upwards into the sky with a velocity of 15 m/s, to what maximum height will the ball reach?

When a stone is dropped from a bridge over a river into the water, after 2.5 seconds the sound of the stone hitting the surface of the water is heard. Calculate the height of the bridge from the surface of the water.

A feather and a coin released from the same height at the same time do not reach the ground at the same time. What is the cause of it?

Under what condition with the object weight 16.7 N on the moon?

Write down the factors that influence acceleration due to gravity.

Why is Newton's law of gravitation called the universal law?

How does gravity differ from gravitation?

The gravitational constant is a universal constant. Give reason.

A stone released from our hands falls towards the earth. Why?

If 1 kg and 10 kg spherical metallic balls are dropped from the same height on the moon then, they reach the ground at the same time. Explain.

The value of 'g' varies from place to place on the earth. Explain this statement.

The value of 'g' is greater at the poles of the earth than at the equator. Explain this statement.

What is the weight of a body having mass 100 kg on the moon?

"Role of gravitational force is very important for the birth and death of a star." Justify the statement.

The acceleration due to gravity of three heavenly bodies are given in the table alongside.

1. Calculate the velocity of object falling freely towards the surface of B in 5th second.
2. If a man can lift 50 kg mass on the surface of the earth, how much mass can he lift on the surface of C?
3. Why are there big craters on the surface of heavenly body of C?
4. Although the mass of Jupiter is 319 times of the mass of the earth, but its acceleration due to gravity does not increase in the same ratio, why?

What is the weight of body on the moon surface if its weight is 150 N on the earth surface?

'Birth and death of stars was not possible in the absence of gravitational force', justify the statement in two points.

Prove that 'Watt' is derived unit showing the proper relation among the fundamental units involved in it. Check unit wise homogeneity in $\rm S = ut^2 + \frac {1}{2}at^2$.

What change occurs in the gravitational force between two bodies when their masses are kept constant and the distance between their centres is reduced by 3 times?

Prove that unit of gravitational constant is derived unit.

A man found 90 N weight of an object of 9 kg mass at a place. From the same place the object was dropped down for 2 s to reach on the ground assuming air resistance is zero;

1. From what height did the object drop?
2. If a stone of 500 g is dropped down from the same heights, how long does it take to reach the ground? Explain with reason.

What is the reason of increasing acceleration due to gravity, if the earth is compressed to the size of the moon?

Mass of the objects A and B as shown in the diagram are 2,500 kg and 4,000 kg respectively.

1. Calculate the gravitational force between the objects A and B.
2. If acceleration due to gravity on body 'A' is 9.8 m/s$^2$ when it is on the surface of the earth? At which height from the surface of earth the body 'A' should be taken so that the acceleration due to gravity is 4 m/s$^2$?

Which formula will you use to find out height from the earth surface from where a stone is dropped down and time taken by the stone to reach the ground is known?

Rita and Pema dropped stone from the top of two different towers standing nearby. Rita dropped the stone of mass 1 Kg. After Is time Pema dropped the stone of mass 1.5 Kg which reached the ground 0.46s later than the Rita's stone. If the tower from where Rita dropped the stone is 60 m high, what is the height of tower from where Pema dropped the stone?

What is gravity?

State the Newton's universal law of gravitation.

Write the nature of gravitational force.

Define gravitational constant (G).

Under what conditions is the value of gravitational force equal to gravitational constant (F=G)?

Write two effects of gravitational force.

Mathematically present the difference in the gravitational force between two objects when the mass of each is made double and the distance between them is made on fourth of their initial distance.

What is gravitational force?

What is free fall? Give two examples of it.

Under what conditions is an object said to be in free fall?

Write the conclusions of the feather and coin experiment.

What is weightlessness?

Mention any four effects of gravitational force.

Prove that acceleration due to the gravity of the Earth is inversely proportional to the square of its radius $\rm \left ( g \propto \frac{1}{R^2} \right )$.

Mention the factors that influence acceleration due to gravity.

The acceleration due to the gravity on the Earth's surface is 9.8 ms^-2. What does this mean?

The mass of the Moon is about 1/81 times the mass of the Earth and its radius is about 37/10 times the radius of the Earth. If the earth is squeezed to the size of the moon, what will be the effect on its acceleration due to gravity? Explain with the help of mathematical calculation.

The acceleration due to gravity of an object of mass 1 kg in outer space is 2m/s². What is the acceleration due to gravity of another object of mass 10 kg at the same point? Justify with arguments.

A man first measures the mass and weight of an object in the mountain and then in the Terai. Compare the data that he obtains.

A student suggests a trick for gaining profit in a business. He suggests buying organes from the mountain and selling them to Terai at the cost price. If a beam balance is used during this transaction, explain, based on scientific fact, whether his trick goes wrong or right.

How is it possible to have a safe landing while jumping from a flying airplane using a parachute? Is it possible to have a safe landing on the moon in the same way? Explain with reasons.

The acceleration of an object moving on the earth is inversely proportional to the mass of the object, but for an object falling towards the surface of the earth, the acceleration does not depend on the mass of the object, why?

What is the relation between the distance between two objects (d) and the gravitational force (F) produced between them?

What is the change in the gravitational force between two objects when their mass is doubled?

If the gravitational force between two objects on Earth is 60 N, what is the gravitational force between those two objects on the moon?

Which one of the following statements is correct?

At which of the following places do you weigh the most?

The radius of the Earth is 6371 km and the weight of an object on the Earth is 800 N. What is the weight of the object at a height of 6371 km from the surface of the earth?

If the mass and the radius of a celestial body are two times the mass and the radius of the earth respectively, what is the value of acceleration due to the gravity of that body?

What will be the weight of a man on the moon if his weight on the Earth is 750 N? (The acceleration due to the gravity of the moon = 1.63  $\rm ms^{-2}$)

The mass of a planet B is twice the mass of planet A but its radius is half of the radius of planet A. Similarly, the mass of planet C is half of the mass of planet A, but its radius is twice the radius of planet A. If the weight of an object in planets A, B, and C is W1, W2, and W3, respectively, which of the following order is correct? 

Which one of the following conclusions is correct while observing a freely falling object every second?

Differentiate: Gravitational constant G and acceleration due to gravity

Differentiate: mass and weight

Acceleration due to gravity is not the same in all parts of the earth.

Jumping from a significant height may cause more injury.

Mass of Jupiter is about 319 times the mass of the Earth, but its acceleration due to gravity is only about 2.6 times the acceleration due to gravity of the Earth. Why?

Among the objects dropped from the same height in the polar region and the equatorial region of the earth, the object dropped in the polar region falls faster. Why?

Out of the two paper sheets, one is folded to form a ball. If the paper ball and the sheet of paper are dropped simultaneously in the air, the folded paper will fall faster. Why?

When a marble and a feather are dropped simultaneously in a vacuum, they reach the ground together (at the same time). Why?

As you climb Mount Everest, the weight of the goods that you carry decreases. Give reason.

It is difficult to lift a big stone on the surface of the earth, but it is easy to lift a smaller one. Why?

Mass of an object remains constant but its weight varies from place to place. Give reason.

One will have an eerie feeling when he/she moves down while playing a Rote Ping. Why?

What is gravity?

Write the nature of gravitational force.

The masses of objects A and B are 20 kg and 40 kg respectively. If the distance between their centers is 5 m, calculate the gravitational force produced between them.

Mass of the Sun and Jupiter are $\rm 2 \times 10^{30}$ and $\rm 1.9 \times 10^{27}$ kg respectively. If the distance between Sun and Jupiter is $\rm 1.8 \times 10^{8}$ km, calculate the gravitational force between Sun and Jupiter.

The Gravitational force produced between the Earth and the Moon is $\rm 2.01 \times 10^{20}$ N. If the distance between these two masses is $\rm 3.84 \times 10^{5}$ km and the mass of the earth is $\rm 5.972 \times 10^{24}$ kg, calculate the mass of the moon.

The mass of the moon is $\rm 7.342 \times 10^{22}$ kg. If the average distance between the earth and the moon is 384400 km, calculate the gravitational force exerted by the moon on every kilogram of water on the surface of the earth.

If the mass of the moon is $\rm 7.342 \times 10^{22}$ kg and its radius is 1737 km, calculate its acceleration due to gravity.

Mass of the Earth is $\rm 5.972 \times 10^{24}$ kg and the diameter of the moon is 3474 km. If the earth is compressed to the size of the moon, how many times will be the change in acceleration due to gravity of the earth so formed than that of the real Earth?

If the mass of Mars is $\rm 6.4 \times 10^{23}$ and its radius is 3389 km, calculate its acceleration due to gravity. What is the weight of an object of mass 200 kg on the surface of Mars?

The acceleration due to the gravity of the earth is $\rm 9.8 ms^{-2}$. If the mass of Jupiter is 319 times the mass of the Earth and its radius is 11 times the radius of the Earth, calculate the acceleration due to the gravity of Jupiter. What is the weight of an object of mass 100 kg on Jupiter?

The Gravitational force produced between the Earth and the Sun is $\rm 3.54 \times 10^{22}$ N. If the masses of the Earth and the Sun are $\rm 5.972 \times 10^{24}$ kg and $\rm 2 \times 10^{30}$ kg respectively, what is the distance between them?

The Earth's mass is $\rm 5.972 \times 10^{24}$ kg and its radius is 6371 km. If the height of Mt. Everest is 8848.86 m from the sea level, calculate the weight of an object of mass 10 kg at the peak of Mt. Everest.

The acceleration due to gravity of the Mars is $\rm 3.75 ms^{-2}$. How much mass can a weight-lifter lift on Mars who can lift 100 kg mass on the Earth?

If a stone is dropped from a height of 15 m, how long will it take to reach the ground? Calculate the velocity of the stone when it hits the ground.

If a cricket ball is thrown vertically upwards into the sky with a velocity of 15 m/s, to what maximum height will the ball reach?

When a stone is dropped from a bridge over a river into the water, after 2.5 seconds the sound of the stone hitting the surface of the water is heard. Calculate the height of the bridge from the surface of the water.

A feather and a coin released from the same height at the same time do not reach the ground at the same time. What is the cause of it?

Under what condition with the object weight 16.7 N on the moon?

Write down the factors that influence acceleration due to gravity.

Why is Newton's law of gravitation called the universal law?

How does gravity differ from gravitation?

The gravitational constant is a universal constant. Give reason.

A stone released from our hands falls towards the earth. Why?

If 1 kg and 10 kg spherical metallic balls are dropped from the same height on the moon then, they reach the ground at the same time. Explain.

The value of 'g' varies from place to place on the earth. Explain this statement.

The value of 'g' is greater at the poles of the earth than at the equator. Explain this statement.

What is the weight of a body having mass 100 kg on the moon?

"Role of gravitational force is very important for the birth and death of a star." Justify the statement.

The acceleration due to gravity of three heavenly bodies are given in the table alongside.

1. Calculate the velocity of object falling freely towards the surface of B in 5th second.
2. If a man can lift 50 kg mass on the surface of the earth, how much mass can he lift on the surface of C?
3. Why are there big craters on the surface of heavenly body of C?
4. Although the mass of Jupiter is 319 times of the mass of the earth, but its acceleration due to gravity does not increase in the same ratio, why?

What is the weight of body on the moon surface if its weight is 150 N on the earth surface?

'Birth and death of stars was not possible in the absence of gravitational force', justify the statement in two points.

Prove that 'Watt' is derived unit showing the proper relation among the fundamental units involved in it. Check unit wise homogeneity in $\rm S = ut^2 + \frac {1}{2}at^2$.

What change occurs in the gravitational force between two bodies when their masses are kept constant and the distance between their centres is reduced by 3 times?

Prove that unit of gravitational constant is derived unit.

A man found 90 N weight of an object of 9 kg mass at a place. From the same place the object was dropped down for 2 s to reach on the ground assuming air resistance is zero;

1. From what height did the object drop?
2. If a stone of 500 g is dropped down from the same heights, how long does it take to reach the ground? Explain with reason.

What is the reason of increasing acceleration due to gravity, if the earth is compressed to the size of the moon?

Mass of the objects A and B as shown in the diagram are 2,500 kg and 4,000 kg respectively.

1. Calculate the gravitational force between the objects A and B.
2. If acceleration due to gravity on body 'A' is 9.8 m/s$^2$ when it is on the surface of the earth? At which height from the surface of earth the body 'A' should be taken so that the acceleration due to gravity is 4 m/s$^2$?

Which formula will you use to find out height from the earth surface from where a stone is dropped down and time taken by the stone to reach the ground is known?

Rita and Pema dropped stone from the top of two different towers standing nearby. Rita dropped the stone of mass 1 Kg. After Is time Pema dropped the stone of mass 1.5 Kg which reached the ground 0.46s later than the Rita's stone. If the tower from where Rita dropped the stone is 60 m high, what is the height of tower from where Pema dropped the stone?