Exercises

What happens to the force between two objects, if the distance between the objects is doubled and tripled?

What happens to the force between two objects, if the masses of both objects are doubled?

A stone is allowed to fall from the top of a tower $100 \mathrm{m}$ high and at the same time, another stone is projected vertically upwards from the ground with a velocity of$25 \mathrm{m}/\mathrm{s}$. Calculate when and where the two stones will meet. (Use  $g = 10 \mathrm{m}/{\mathrm{s}}^2$)

A ball thrown up vertically returns to the thrower after 6 s. (Use g = $10 \mathrm{m}/{\mathrm{s}}^2$)Find
(a) the velocity with which it was thrown up,
(b) the maximum height it reaches, and
(c) its position after 4 s.

In what direction does the buoyant force on an object immersed in a liquid act?

Why does a block of plastic released under water come up to the surface of the water?

The volume of $50 \mathrm{g}$ of a substance is $20 {\mathrm{cm}}^3$. If the density of water is $1 \mathrm{g} {\mathrm{cm}}^{-3}$ will the substance float or sink?

The volume of a $500 \mathrm{g}$sealed packet is $350 {\mathrm{cm}}^3$. Will the packet float or sink in water if the density of water is $1 \mathrm{g} {\mathrm{cm}}^{-3}$? What will be the mass of the water displaced by this packet?