



 
Julius, The circumference of the 8 inch pulley is 2 π r = 16 π inches. The 8 inch pulley is revolving at the rate of 21 revolutions every second. Hence in one second the belt, and thus the fly, travels 21 × 16 π inches and therefore the fly is moving at 21 × 16 π inches per second. How long will it take for the fly to travel a mile? I converted the angular velocity of the 8 inch pulley (in revolutions per second) to linear velocity of the belt (in inches per second). The belt is moving at this velocity over the 6 inch pulley also. Use this to calculate the angular velocity of the 6 inch pulley. Penny  


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