math

One wheel has a diameter of 30 inches and a second wheel has a diameter of 20 inches. The first wheel traveled a certain distance in 240 revolutions. In how many revolutions did the second wheel travel the same distance?

not just an answer please

A.120
B.160
C.360
D.420
E.480

asked by vincent
  1. short way:
    the number of revolutions varies inversely with the diameter of the wheel
    i.e. the larger the wheel the smaller the number of revs.

    R1/R2 = C2/C1
    240/R2 = 20/30
    20R2 = 7200
    R2 = 360

    or

    distance covered by first wheel = 2π(15)(240) = 7200π inches

    circumference of 2nd wheel = 2π(10) = 20π inches
    for the same distance of 7200π inches
    number of revolutions = 7200π/(20π) = 360 revs

    posted by Reiny
  2. c.360

    posted by Dominique

Respond to this Question

First Name

Your Answer

Similar Questions

  1. Physics

    There are two wheels with diameter 30 inches and 20 inches. The first wheel covers a certain distance in 240 revolutions. In how many revoluions would the second wheel cover the same distance?
  2. Geometry

    A wheel of a motor home has a diameter of 32 inches. How far will the wheel travel in 5 revolutions?
  3. Math

    Math - Zo, Wednesday, April 22, 2015 at 8:44pm A wheel has s radius of 9 inches. If the wheel is rolled on a flat surface, how many revolutions will it take for the wheel to travel 90 ~ pie inches
  4. Trig

    Jane has a bike with a 22-inch rear wheel. The wheel sprocket is 3 inches in diameter and the pedal sprocket is 4 inches in diameter (the sprockets hold the chain.) How fast in miles per hour is she going if she pedals at a rate
  5. Statistics

    The inside diameter of the automobile wheel bearing sets at a factory is expected to be normally distributed with a mean of 1.30inches and a standard deviation of 0.04 inches. What is the probability that a randomly selected wheel
  6. Math

    A bicycle wheel is 30 inches in diameter. a. to the nearest revolution, how many times will the wheel turn if the bicycle is ridden for 3 miles. b. suppose the wheel turns at a constant rate of 2.75 revolutions per second. What is
  7. trigonometry

    these two are the same type of questions but i have no clue how to figure out the answer. i have tried drawing it out but don't know what to do after that. 1. a bicycle with a 28-inch wheel(diameter) travels a distance of 800
  8. math

    The wheel in the figure has a diameter of 1 yard. The wheel is rolled forward as shown until the point marked A has undergone exactly one revolution around the wheel's axis. What number is represented by the distance in yards that
  9. Math

    How many feet does a wheel with a diameter of 20 inches travel after one, five, and 30 revolutions?
  10. algebra

    a wheel with a diameter of 12 inches is spinning at 10 revolutions per mnute. In one minute, a point on the edge of the circle would have traveled a distance of ???

More Similar Questions