Momentum

Formula - $p=mv$
- Momentum is a vector quantity
- Measured in $kg \space m\space s^{-1}$
- Is a conserved quantity
Conservation of momentum
- $\sum\limits P$ before = $\sum\limits P$ after.
- i.e $m_{1}u_{1}+m_{2}u_{2}=m_{1}v_{1}+m_{2}v_{2}$
You must put your answer in scientific notation #testanswer
- i.e $100kg \space m \space s^{-1}$ should be $10.0 \times 10^{2}$
- Also, $ms^{-1}$ is milliseconds, so you should write $m \space s^{-1}$ for meters per second
Question
- A truck of mass $1.50t$ is travelling west at $110 \space kmh^{-1}$ when it has a head on collision with a car of $750kg$ travelling $74 kmh^{-1}$ east. If the final velocity of the truck is $46.7kmh^{-1}$ west, what is the final velocity of the car in $kmh^{-1}$.
$\triangle P=P_{Final}-P_{Initial}$
- Two dimensional problem.

Is measured in $kg \space m\space s^{-2}$ which is actually just $N$
Impulse, on the other hand is measured in $Ns$ - Newton seconds, not seconds per newton
- It is formulated $F\triangle t=m(v-u)$
- Because $F=ma$, and $a=\frac{\triangle v}{\triangle t}$
- $F\triangle t=m \triangle v$
- then, $F\triangle t=m(v-u)$