A CD has a diameter of 12.0 cm. If the CD is rotating at a constant angular speed of 200 revolutions per minute, then the tangential velocity of a point on the circumference is:

Hi there!

Converting from angular velocity to tangential velocity can be done by:

v = ωr

v = tangential velocity (m/s)

ω = angular velocity (rad/sec)

r = radius (m)

Convert 12 cm to meters:

100 cm = 1 m

12 cm = 0.12 m

Now, convert rev/min to rad/sec:

v = 20.94 · 0.12 = 2.51 m/s

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.