If a body is in motion,is it necessary that it is being acted upon by a force?

Kicking a football requires less force than kicking a basketball. Why?

Inertia is that property of a body by virtue of which the body is

Write answers to the following:
$(i)$ Mention the direction in which the force of friction acts on a moving body. State its units.
$(ii)$ Name the property of bodies (or objects) to resist a change in their state of rest or of motion. Name the quantity that is a measure of this property.
$(iii)$ Name the physical quantity whose unit is $kg\, m s^{-1}$. Define this quantity.

There are three solids made up of aluminium,steel,and wood,of the same shape and same volume. Which of them would have the highest inertia?

$A$ body projected horizontally moves with the same horizontal velocity although it is under the action of the force of gravity,why?