A computerized spin balance machine rotates a 25-inch-diameter tire at 430 revolutions per minute.

Question

(a) Find the road speed (in miles per hour) at which the tire is being balanced. (Round your answer to two decimal places.)

_______mph

(b) At what rate should the spin balance machine be set so that the tire is being tested for 45 miles per hour? (Round your answer to two decimal places.)

_________ revolutions per minute

Answer 1

(a) Find the road speed (in miles per hour) at which the tire is being balanced. (Round your answer to two decimal places.)

25 x pi x 430 (in/min).(1ft/12in).(1mi/5280ft).60(min/hr) = 31.98 (mi/hr)

(b) At what rate should the spin balance machine be set so that the tire is being tested for 45 miles per hour? (Round your answer to two decimal places.)

430 (rev/min)/31.98(mi/hr) = x/45 or x = 605.06 (rev/min)