Figure P35.4 shows an apparatus used to measure the speed distribution of gas molecules. It consists of two slotted rotating disks separated by a distance d, with the slots displaced by the angle &. Suppose the speed of light is measured by sending a light beam from the left through this apparatus.
(a) Show that a light beam will be seen in the detector (that is, will make it through both slots) only if its speed is given by c = wd/θ, where w is the angular speed of the disks and & is measured in radians.
(b) What is the measured speed of light if the distance between the two slotted rotating disks is 2.50 m, the slot in the second disk is displaced 1/60 of one degree from the slot in the first disk, and the disks are rotating at 5 555 rev/s?

Transcribed Image Text:

Beam Motor Detector