Dr. Brown Lecture Physics 53
7 Sep 2010 11:40 - 12:55
candy
start inertial reference frames and symmetry
use for inclined plane, atwood , conical pendulum
recite-able Inertia, N2, Reaction
symmetry / invariance --
time t' = t - t_0 -- \Delta t ==> dt' = dt ! same event
length x' = x + x_0 ==> dx' = dx
dx'/dt = dx/dt
dv'/dt ...
also invar under rotation ...
inertial frame [mutually consist -- though circular defn]
draws rest frame --> and const. velocity frame
x = x' + v_0 t
differentiate once and twice [accel measured is SAME in both!]
N2 invarient under inertial frame changes
what if non-inertial frame? v = v' + v_0(t)
F_tot = ma = ma' + ma_0 "pseudo-forces"
artillary, hurricanes, ... examples where accel frame needed for analysis
problem
1. inclined plane -- frictionless
2. atwood
3. swing in circle [kung pow] -- constant speed -- a_r = v^2/r