A Device Used to Measure the Speed, V, of Molecules $\omega$

question 70

Multiple Choice

A device used to measure the speed, v, of molecules is shown below. When the cylinder is rotated, only molecules that are of the right speed will pass through the slanted slot and be pickup by the detector. Drive an expression for the speed v in terms of the angular speed, $\omega$ , $\phi$ , and L. L is the length of the cylinder and $\phi$ is the angle subtended by the slanted slot.