temp:prelec:momentum

Pre-lecture: Momentum and Momentum Principle

Changes in motion; you pay attention to how an object changes it position
Define momentum - some objects are easier to change their motion than others
- $\vec{p} = \gamma m \vec{v}$ is a vector concept; points in direction of velocity vector for a system; complete and alway applies
- Define $\gamma$
- $\gamma$ starts to matter at high speeds; less than about 300 km/s $\gamma \approx 1$
- $\vec{p}=m\vec{v}$
The motion of a system is governed by the momentum prinicple
- Big idea: Forces cause changes in a system's momentum; specifically the net force (define momentarily)
- N1: An object that experiences no net force moves with constant velocity and vice-versa
- N2 (MP): The quantitative description is $\Delta \vec{p} = \vec{F}_{net}\Delta t$ .
  - What is a force…and…the net force?
- Where the's calculus?
  - This description is an average force over a time interval; if the time interval shrinks, we get that the net force is the derivative of the momentum.
Another way to represent: force vs time graphs
- More calculus area under the curve gives change in momentum