What happens to the force between two objects, if (iii) the masses of both objects are doubled?
2.
A ball thrown up vertically returns to the thrower after $6$ s. Find (b) the maximum height it reaches, and
3.
What happens to the force between two objects, if (ii) the distance between the objects is doubled and tripled?
4.
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?
5.
A ball thrown up vertically returns to the thrower after $6$ s. Find (a) the velocity with which it was thrown up,
6.
A stone is released from the top of a tower of height $19.6$ m. Calculate its final velocity just before touching the ground.
7.
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.)
8.
Calculate the force of gravitation between the earth and the Sun, given that the mass of the earth = $6 \times 10^{24}$ kg and of the Sun = $2 \times 10^{30}$ kg. The average distance between the two is $1.5 \times 10^{11}$ m.
9.
A ball thrown up vertically returns to the thrower after $6$ s. Find (c) its position after $4$ s.
10.
Why will a sheet of paper fall slower than one that is crumpled into a ball?
11.
In what direction does the buoyant force on an object immersed in a liquid act?
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.
A stone is allowed to fall from the top of a tower $100$ m high and at the same time another stone is projected vertically upwards from the ground with a velocity of $25$ m/s. Calculate when and where the two stones will meet.
14.
What is the importance of universal law of gravitation?
15.
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?
16.
What is the acceleration of free fall?
17.
How does the force of gravitation between two objects change when the distance between them is reduced to half ?
18.
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.
19.
Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?
20.
A ball is thrown vertically upwards with a velocity of $49$ m/s. Calculate (i) the maximum height to which it rises,
