The impulse momentum theorem is a variation of Newton’s Second Law.

## Newton’s Second Law

\(\color{black}{\Sigma \vec{F} = m \vec{a}}\)

We have seen that Newton’s Second Law is very useful in solving problems involving forces and accelerations. Often, though, we have no way of measuring either the forces or the acceleration directly. On the other hand, we can often measure the velocity. If not, we use clever tricks like measuring skid marks to determine the velocity of a car before a wreck.

## The Impulse Momentum Theorem

In this section, we will investigate a variation of Newton’s Second Law called the Impulse-Momentum Theorem.

\(\color{black}{ \Sigma \vec{F} \Delta t = \Delta \vec{p}}\)

First, we will derive it. Then we will use it to solve problems.