The inertia of an object tends to cause the object

Two identical bullets are fired,one by a light rifle and another by a heavy rifle with the same force. Which rifle will hurt the shoulder more and why?

$(i)$ Name the property of bodies to resist a change in their velocity.
$(ii)$ What is the relationship between force and acceleration?
$(iii)$ What name is given to the product of mass and velocity of a body?
$(iv)$ Which physical quantity corresponds to the rate of change of momentum?
$(v)$ Name the principle on which a rocket works.

Air is blown onto a sail attached to a boat from an electric fan placed on the boat. Will the boat start moving?

Explain the following:
$(i)$ Why do we jerk wet clothes before spreading them on a line?
$(ii)$ Why does dust fly off when a carpet is hit with a stick?
$(iii)$ Why do fruits fall off the branches in a strong wind?
$(iv)$ Why does a pillion rider fall forward when the driver of a two-wheeler suddenly applies brakes?

Define $1\, kg$ weight and express it in newton.