Phys 53 Lecture 2 Sep 2010  Dr. Robert Brown

Earl ;(

limit defns in 2D
newt's laws in shorter notation
1. inertia if F_ = 0 then v = const
2. F = ma
3. reaction 

[note -- rob forgot lighting rule -- board lights!]

laws of nature
1. strong nuclear   only in nucleus, 10^-15 m
2. Electromag (us!)
3. weak (only in nucleons)
4. grav

force rules
1. grav near surface of earth  \vec{F}_g = -mg \hat{y}   g approx 10 m/s^2
demos -- spring SHO -- pend (bowling ball)
2. hooke's
3. normal   (constraint force -- w/in common sense limits)
4. tension (another constraint force
5. friction, drag

now to apply ... 

prob 1   drop ball , m  off duke chapel    1.  draw pic  2. decorate (forces, ...  3.     4.    5.   6.

prob 2   cannonball , 2D  proj. motion