Grimer wrote.
>
> You seem very fond of calculating things, Fred. How about
> working out the relation between size and power output?
>
Actually at the optimum 0.2 Torr pressure for the Radiometer
the kinetic theory equation for the number of atoms-molecules
striking a unit surface area per second is:
0.25 * (N/V) * v *Area
At 760 torr 300 K, N/V = 2.69E25 atoms-molecules per cubic meter
1/2 mv^2 = kT, for Argon-40 v = [4.14E-21/(0.5*40*1.66E-27)]^1/2 =
353 meters/sec.
At 0.2 torr N/V = 7.07E21 atoms-molecules per cubic meter.
So, 0.25 * 7.07E21 * 353 = 6.24E23 molecules/meter^2 per sec.
Recoil mv = 2 * 6.24E23 * 40 * 1.66E-27 * 353 = 0.083 newtons/meter^2 force
Not much torque there,if I didn't goof, Frank.
Fred
