CD dust specks: which has greater centripetal acceleration?

Question

CD dust specks: which has greater centripetal acceleration??  
A. Edge speck  
B. Mid radius speck  
C. Zero  
D. Same

Accepted Answer

Correct Answer: (A)Edge speck. 
Rationale: The dust speck on the edge of the CD has the greater centripetal acceleration.When a CD spins at a constant angular velocity, every point on the disc completes each rotation in the same amount of time. However, points farther from the center move in a larger circle. Centripetal acceleration depends directly on the distance from the axis of rotation, so location matters.A) Edge speckCentripetal acceleration is given by the relationship:centripetal acceleration equals angular velocity squared multiplied by radiuswhere angular velocity is the same for all points on the CD and radius is the distance from the center. At the edge of the CD, the radius is largest, so the centripetal acceleration is greatest.B) Mid-radius speckThis speck has a smaller radius than the edge speck. With the same angular velocity but a smaller radius, its centripetal acceleration is smaller.C) ZeroAny object moving in a circular path has a nonzero centripetal acceleration because its direction of motion is continuously changing. A dust speck on a rotating CD is therefore never at zero centripetal acceleration.D) SameCentripetal acceleration would only be the same if the specks were at the same radius. Since one speck is closer to the center and the other is at the edge, their accelerations are different.ConclusionAt constant angular velocity, centripetal acceleration increases with radius. The dust speck on the edge of the CD, being farthest from the center, experiences the greatest centripetal acceleration.

CD dust specks: which has greater centripetal acceleration?

A
Edge speck

B
Mid radius speck

C
Zero

D
Same

The dust speck on the edge of the CD has the greater centripetal acceleration.

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CD dust specks: which has greater centripetal acceleration?

A Edge speck B Mid radius speck C Zero D Same

The dust speck on the edge of the CD has the greater centripetal acceleration.

Topic Flashcards

Mini Quiz

Related Questions

A
Edge speck

B
Mid radius speck

C
Zero

D
Same