When a fruit falls from a tree,

The earth attracts a body with a force of 10 N. with what force does that the body attracts the earth?

Newton's law of gravitation is applicable to

All bodies whether large or small fall with the

A stone of mass 1 kg is thrown vertically upwards with a velocity of 19.6 ms^-1 . If the resistance by air is neglected, it will rise to a maximum height of

A sphere of mass 40 kg is attracted by a second sphere of mass 60 kg with a force equal to 4 x 10^-5 N. If G = 6 x 10^-11 Nm²/kg² . Calculate the distance between the two spheres.

Compare the gravitational forces exerted by the sun and the moon on the earth. Which exerts a greater force and by how many times?

You stand on loose sand. Your feet go deep into the sand. Now, lie down on the sand. You will find that your body will not go deep in the sand. Give reason for the difference in the two cases.

At what height from the surface of g the earth, will the value of g be reduced by 36% from the value at the surface? Radius of the earth = 6400 km.

Suppose your weight on the surface of the earth is 600 N and are taken to a height equal to the radius of the earth, then what will be your weight there?

If a fresh egg is put into a beaker filled with water, it sinks. On dissolving a lot of salt in the water, the egg begins to rise and floats. Why?

A cubical tub of side 2 m is full of water. Calculate the total thrust and pressure at the bottom of tank due to water. (Take, density of water = 1000 kg m^-3 and g = 10 ms^-2)

A ball is thrown with some speed u mls. Show that under the free fall, it will fall on the ground with same speed.

Mohit throws a ball horizontally while Shobhit throws a ball vertically downwards from a tower. Both of them do so in an attempt to see who hits the stone on ground first. After that, they try to reason their findings.
Read the above passage and answer the following questions:
(i) Which ball reaches the ground first?
(ii) What are the values shown by Mohit and Shobhit?
(iii) What is the relation of g with G?

Shruti and Kriti were performing the experiment to find the pressure exerted by a cuboid kept on sand with its different faces. Shruti shared her thoughts with Kriti and told her that, since the teacher had explained about pressure and area, therefore she could guess the results.
(i) How can you relate pressure applied by an object with its area?
(ii) What would be the observation of Shruti and Kriti?
(iii) Which qualities about Shruti do you observe from here?

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?

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.

(i) At some moment, two giant planets jupiter and saturn of the solar system are in the same line as seen from the earth. Find the total gravitational force due to them on a person of mass 50 kg on the earth. Could the force due to the planets be important?
Mass of the jupiter = 2 x 10²⁷ kg
Mass of the saturn = 6 x 10²⁶ kg
Distance of jupiter from the earth
= 6.3x 10¹¹ m
Distance of saturn from the earth
= 1.28 x 1012m
Gravitational constant,
G = 6.67 x 10^-11N -m² /kg²
Acceleration due to gravity on the earth
=9.8 m/s²
(ii) A bag of sugar weighs w at a certain place on the equator. If this bag is taken to Antarctica, then will it weigh the same or more or less. Give a reason for your answer.

(i) A person weighs 110.84 N on the moon, whose acceleration due to gravity is 1/6 of that the earth. If the value of g on the earth is 9.8 m/s², then calculate
(a) g on the moon
(b) mass of person on the moon
(c) weight of person on the earth
(ii) How does the value of g on the earth is related to the mass of the earth and its radius? Derive it.