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