On Earth,how much force is needed to lift an object of mass $100 \,g$ (in $,N$)?

Calculate the force of gravitation between two objects of masses $10 \; kg$ and $20 \; kg$ at a distance of $10 \; m$ from each other. $\left[G = 6.67 \times 10^{-11} \; Nm^2 kg^{-2}\right]$

The gravitational force between two objects is $F$. If the masses of both objects are halved without changing the distance between them,then the gravitational force would become:

The weight of an object:

Distinguish between mass and weight of an object. How does the weight of an object change when moving from the equator to the poles? When can the weight of an object be zero?

Define free fall.