Introduction to Gravitation

What is the universal law of gravity?

The value of the universal gravitational constant is _____$\times {10}^{-11} \mathrm{N} {\mathrm{m}}^2 {\mathrm{kg}}^{-2}$. (Answer upto two decimal places).

The earth revolves around the sun due to Earth's gravity. This gravity is balanced by _____ force.

The earth revolves around the sun sue to the presence of _____.(Earth's gravity/ earth's magnetic effect)

Gravitational force is the _____ force in nature.

What is the value of the universal gravitational constant?

Gravitational force is the strongest force.

The force of attraction between two unit masses separated by a unit distance is called

If distance between objects is doubled, the force of gravitation between them becomes _____ ($\frac{1}{2}/\frac{1}{4}$).

Force of _____ (gravitation/acceleration) is responsible for motion of planets around the sun.

The motion of the moon around the earth is due to _____ (gravitational/frictional) force.

Gravitation is a _____ (highest/lowest) range force.

In S.I. unit $G$ = _____.

Why does earth revolve around sun and not move towards sun? Derive an expression for force between sun and earth.

How does force of attraction between two objects depend on their masses and distance between them? A student thought that two bricks tied together would fall faster than a single one under the action of gravity. Do you agree with this hypothesis? Discuss.

If gravitational force of earth suddenly vanished away, what would happen? In which direction will the objects move, if not towards centre of earth?

Which is greater : attraction of earth on $1$ kg iron or attraction of $1$ kg iron on earth? Why? What is meant by saying. "Acceleration due to gravity is $9.8 m/s^2$".

Give reasons : Moon revolves around earth in a fixed orbit.

Throw light on significance of universal law of gravitation.

Distinguish between '$G$' and '$g$'.