Question

A record of radius 15 cm is spinning at 45 revolutions per minute. What is the linear speed, in cm/min, of a point on the rim of the record?

Answer 1

What you need to know for this case is that the linear velocity is defined as the product of the angular velocity by the radius.
 We have then:
 v = w * r
 Substituting the values:
 v = (45) * (15) = 675
 v = 675 cm / min
 answer:
 The linear speed, in cm / min, of a point on the rim of the record is:
 v = 675 cm / min