Each tire of an automobile has a radius of 2 feet How many r
     Each tire of an automobile has a radius of 2 feet. How many revolutions per minute (rpm) does a tire make when the automobile is travelling at a speed of 116 feet per sec? Round your answer to the nearest tenth. 
  
  Solution
radius = 2 feet
speed = 116 feet / sec
circumference of tire = 2pi*r = 2*pi* 2 = 12.56 feet
revolutions per minute = 116*60 / 12.56 = 554.14
it makes 554 revolutions per minute

