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Answer:
- 16,965 mm/min
- 90π ≈ 282.7 radians/min
Explanation:
The circumference of the CD is ...
C = πd
C = π(120 mm) ≈ 376.99 mm
This is the distance a point on the edge of the CD will travel when making one revolution. It will travel 45 times this far when making 45 revolutions:
(376.99 mm/rev)(45 rev/min) ≈ 16,965 mm/min
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There are 2π radians in each revolution, so the angular speed is ...
(2π rad/rev)(45 rev/min) = 90π rad/min ≈ 282.7 rad/min