SOLUTION: A tire for a car is 28 inches in diameter. If the car is traveling at a speed of 20 mi/hr, find the number of revolutions the tire makes per minute. (Round your answer to the neare

Algebra ->  Trigonometry-basics -> SOLUTION: A tire for a car is 28 inches in diameter. If the car is traveling at a speed of 20 mi/hr, find the number of revolutions the tire makes per minute. (Round your answer to the neare      Log On


   

Question 897087: A tire for a car is 28 inches in diameter. If the car is traveling at a speed of 20 mi/hr, find the number of revolutions the tire makes per minute. (Round your answer to the nearest hundredth.)
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The circumference is:
+pi%2Ad+=+3.141%2A28+
+pi%2Ad+=+87.948+ in
One circumference is traced out in one revolution
------------------------
In words:
( revolutions / minute ) x ( inches / revolution ) = inches / minute
( revolutions / minute ) = ( inches / minute ) / ( inches / revolution )
( revolutions / minute ) = ( inches / minute ) / 87.948
--------------------
( inches / minute ) = ( inches / feet ) x ( feet / mile ) x ( miles / hour ) x ( hours / minute )
( inches / minute ) = +%28+12%2F1+%29%2A%28+5280%2F1+%29%2A20%2A%28+1%2F60+%29+
( inches / minute ) = +21120+
------------------------------
( revolutions / minute ) = +21120+%2F+87.948+
+21120+%2F+87.948+=+240.1419+
The tire makes 240.14 RPM
Hope I got it