Average power absorbed

1
Average power absorbed
This is instantaneous power
Average power over one period T
2
The second term is zero
So the phase lag of the response tells us how
much power is absorbed
3
Mechanical Oscillator Atomic Force Microscope
This cantilever oscillates as its tip is dragged
over a surface tapping mode
This is the instrument itself, built to operate
at low temperatures in ultra-high vacuum
phase
amplitude
Atomic resolution! This is the surface of silicon
Measuring the phase lag of a driven mechanical
oscillator at different locations close to a
surface tells us information we could not get
from the amplitude!
4
Summary of Chapter 2
5
(No Transcript)
6
Ordinary Differential Equations you MUST KNOW
You can always use a power series approach to
solving these diff. eqs.,
But inspection works best for me always suspect
that the solution is some kind of exponential,
then work out the coefficient.
What function has no curvature?