Lakhmir Singh and Manjit Kaur Solutions for Chapter: Gravitation, Exercise 5: Questions Based on High Order Thinking Skills (HOTS)

If the distance between two masses is increased by $5$, by what factor would the mass of one of them, have to be altered to maintain the same gravitational force? Would this be an increase or decrease in mass

Universal law of gravitation states that every object exerts a gravitational force of attraction on every other object. If this is true, why don't we notice such forces? Why don't the two objects in a room move towards each other due to this force?

Suppose a planet whose mass and radius both are half those of the earth. Calculate the acceleration due to gravity on the surface of this planet.

A coin and a piece of paper are dropped simultaneously from the same height. Which of the two will touch the ground first? What will happen if the coin and the piece of paper are dropped in vacuum? Give reasons for your answer.

A stone and the earth attract each other with an equal and opposite force. Why then we see only the stone falling towards the earth but not the earth rising towards the stone?

What is the actual shape of the orbit of a planet around the sun?  What assumption was made by Newton regarding shape of an orbit of a planet around the sun for deriving his inverse square rule from Kepler's third law of planetary motion?

The value of $g$ at six distances $A$, $B$, $C$, $D$, $E$ and $F$ from the surface of the earth is found to be $3.08$  $\mathrm{m}/{\mathrm{s}}^2$, $9.23$ $\mathrm{m}/{\mathrm{s}}^2$,  $0.57$ $\mathrm{m}/{\mathrm{s}}^2$, $7.34$ $\mathrm{m}/{\mathrm{s}}^2$ $0.30$ $\mathrm{m}/{\mathrm{s}}^2$ and $1.49$ $\mathrm{m}/{\mathrm{s}}^2$  respectively.

Arrange these values of $g$ according to the increasing distances from the surface of the earth (keeping the value of $g$ nearest to the surface of the earth first).

The value of $g$ at six distances $A$, $B$, $C$, $D$, $E$ and $F$ from the surface of the earth are found to be  $3.08$ $\mathrm{m}/{\mathrm{s}}^2$, $9.23$ $\mathrm{m}/{\mathrm{s}}^2$,$0.57$ $\mathrm{m}/{\mathrm{s}}^2$,$7.34$ $\mathrm{m}/{\mathrm{s}}^2$,$0.30$ $\mathrm{m}/{\mathrm{s}}^2$ , and $1.49$ $\mathrm{m}/{\mathrm{s}}^2$​​ respectively.

If the value of distance $F$ be $10000$ $\mathrm{km}$ from the surface of the earth, state whether this distance is deep inside or high up in the sky. Give reasons for your answer.​​​​​