How does the force of gravitation between two objects change when the distance between them is reduced to half ?
2.
A ball thrown up vertically returns to the thrower after $6$ s. Find (a) the velocity with which it was thrown up,
3.
What happens to the force between two objects, if (iii) the masses of both objects are doubled?
4.
In what direction does the buoyant force on an object immersed in a liquid act?
5.
What is the importance of universal law of gravitation?
6.
A ball is thrown vertically upwards with a velocity of $49$ m/s. Calculate (i) the maximum height to which it rises,
7.
Gravitational force on the surface of the moon is only $\frac{1}{6}$ as strong as gravitational force on the earth. What is the weight in newtons of a $10$ kg object on the moon and on the earth?
8.
What is the acceleration of free fall?
9.
Why does a block of plastic released under water come up to the surface of water?
10.
What do we call the gravitational force between the earth and an object?
11.
The volume of $50$ g of a substance is $20$ cm$^3$. If the density of water is $1$ g cm$^{-3}$, will the substance float or sink?
12.
The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with a force that is greater or smaller or the same as the force with which the moon attracts the earth? Why?
13.
If the moon attracts the earth, why does the earth not move towards the moon?
14.
What happens to the force between two objects, if (i) the mass of one object is doubled?
15.
What happens to the force between two objects, if (ii) the distance between the objects is doubled and tripled?
16.
A ball thrown up vertically returns to the thrower after $6$ s. Find (c) its position after $4$ s.
17.
A ball is thrown vertically upwards with a velocity of $49$ m/s. Calculate (ii) the total time it takes to return to the surface of the earth.
18.
A ball thrown up vertically returns to the thrower after $6$ s. Find (b) the maximum height it reaches, and
19.
A stone is thrown vertically upward with an initial velocity of $40$ m/s. Taking $g = 10$ m/s$^2$, find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?
20.
A stone is released from the top of a tower of height $19.6$ m. Calculate its final velocity just before touching the ground.
