Question 1009839
A truck with 18-in.-diameter wheels is traveling at 45 mi/h. 
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(b) How many revolutions per minute do the wheels make?
45 mi/hr = 66 ft/sec = 3960 ft/minute
Each revolution moves the truck the circumference, C = pi*d = 1.5pi feet
Rev/min = 3960/(1.5pi) = 2640/pi
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(a) Find the angular speed of the wheels in rad/min
= 2pi*rpm
= 5280 rad/minute
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Hint: we don't need hints