```P201 Menu

Class_Notes

Newton's Laws

1. Law of Inertia A body naturally moves in a straight line
at constant speed natural means no external influence on body
or:```
`Sum Forces ON body = 0`
```2. Law of Non-Inertia. The net force ON a body causes an acceleration
in direction of net force and of magnitude given by```
`Sum of Forces ON body equals mass x acceleration.`

```3. Law of Action - Reaction.  ALL Forces are interactions
between two bodies (A & B) If body A exerts force on body
B (FAB), then body B exerts a force on body A (FBA) which
is equal and opposite. FBA = - FAB```
`Other examples:`
```Conical Pendulum

Newton's Law for rotation```
```Whirlygig
`Now on to Horse and Wagon`
```
Apply 2nd Law to Wagon (4 wheels)

Path: FHW - 4 fSW = Mw apath
Perp: 4 FSW - FEW = Mw aperp

Apply 2nd Law to Horse (4 feet)

Path: 4 fSH - FWH = Mh apath
Perp: 4 FSH - FEH = Mh aperp```
`Other applications`
`Car Moving to Right`

`Car Coming At You and curving to right (your left)`
`Level Road ..................Banked Road`

```
Now a little quiz about Newton's Laws```
```Concept of Collisions.......Explosions.

Application of Newton's 2nd and 3rd Laws.```
`F = m a  or  F = D(mv)/Dt`
`Or  F Dt = D(mv)`
`Where D = delta (change)`
` mv = momentum`

```so force equals the rate of change of momentum of a body OR
Force acting for a time (Dt) causes a change in momentum.```

```For example, billiards

`B. Glancing Blow`
`Other examples:`
```Shooting guns