An eartly method of measuring the speed of light makes use of a rotating slotted wheel.
A beam of light passes through one of the slots at the outside edge of the wheel, travels to a distant mirror, and returns to the wheel just in time to pass through the next slot in the wheel. One such slotted wheel has a radius of 5.0 cm and 500 slots around its edge. Measurements taken when athe mirror is L = 550 m from the wheel indicate a speed of light of 3.0 x 10^8 km/s.

(a) What is the (constant) angular speed of the wheel?
(b) What is the linear speed of a point on the edge of the wheel?

Explanation:

Distance traveled by light = 2 x 550 m = 1100 m

time taken by light to travel this distance = 1100 / 3 x 10⁸

=  366.67 x 10⁻⁸ s

angle between two consecutive slots = 2π / 500 rad

= .004π

angular velocity of wheel = angle moved / time taken

= .004π / 366.67 x 10⁻⁸

= 1091π radian / s

b )  linear speed of a point on the edge of the wheel

= ω R , r is radius of wheel , ω is angular velocity.

= 1091π x 5 x 10⁻²

= 1712.8 m /s

a.   mass number from atomic number

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm