We are about to use another conservation principle in an
effort to sove a different class of problems. We started with Newton's
Laws of motion (the motion equations, F=ma), then
we developed the Conservation of
Energy Principle (energy before=energy after) and now
we will utilize the Conservation of Momentum
Principle. All three perspectives will allow us to solve
problems when we don't know certain values.

When
acceleration is constant such as a car speeding up at a constant rate.

When
a force is not constant such as the gravitational force, or the force due
to a spring.

The
force exerted on the archer after the arrow is fired.

Linear
Momentum is a vector quantity. A quantity of motion.

Momentum
and Force

Conservation
Of Linear Momentum

Mechanical
Unverse

Collisions
in One Dimension

Momentum
is always conserved.

Kinetic Energy is not necessarily conserved in all
collisions.