An instrument shows the number of revolutions per
minute made by each tire of a car. In each revolution, the
car travels a distance equal to the circumference of one of
its tires. The circumference of each tire is equal to 2πr,
where r is the radius of the tire.
If the radius of each tire on Maria’s car is 0.30 meter,
what is the approximate speed of Maria’s car, to the
nearest kilometer per hour, when the instrument is
showing 779 revolutions per minute?
(1 kilometer = 1000 meters)

  1. 👍 0
  2. 👎 0
  3. 👁 174
asked by harley
  1. tire circumference * rpm * minutes per hour / meters per km

    2 * π * 0.30 * 779 * 60 / 1000

    1. 👍 0
    2. 👎 0
    posted by scott
  2. C = 2pi*r = 6.28 * 0.3 = 1.884 m/rev. = Circumference.

    Speed = 779rev/min * 1.884m/rev. * 1km/1000m * 60min/h = 88 km/h.

    1. 👍 0
    2. 👎 0
    posted by Henry

Respond to this Question

First Name

Your Response

Similar Questions

  1. 10th grade

    as you are driving your car on the freeway, your tires are rotating at a rate of 920 revolutions per minute. The diameter of each tire is 24 inches. What is the total feet traveled per minute?

    asked by kathy on November 30, 2010
  2. geometry

    A bicycle tire has a diameter of 60cm and rotates 33.3 revolutions per minute.How far does a point on the edge of the tire travel in a minute? Use 3.14 for pi.

    asked by Ghislaine on June 17, 2014
  3. Physics

    The warranty on a new tire says that an automobile can travel for a distance of 92,000km before the tire wears out. The radius of the tire is 0.33m. How many revolutions does the tire make before wearing out? hello CJ I think we

    asked by CJ on March 14, 2007
  4. 5th grade Math

    I need help with the question below. A bicyle tire has a diameter of 24 inches. If a tire rotates for 20 revolutions about how far has the bike rider ridden? Use 3.14 for pi. I know to find the circumference you would do 24 x 3.14

    asked by Brandi on March 19, 2012
  5. Trigonometry

    The tires on a car have radius 14 inches. Find the angular speed of the car tire in revolutions per second when it is traveling 70 mph. Find the angular speed at 80 mph. The tires on a car are 15 inches. Find the linear speed of

    asked by Will on January 21, 2012
  6. math

    Dana rode her bicycle 600 miles one summer before she had to replace the tire on her front wheel. The diameter of the front wheel is 24 inches. What is the best estimate of the number of revolutions made by the tire before it had

    asked by Tanya on March 31, 2014
  7. physics

    An automobile tire is rated to last for 45,000 miles. Estimate the number of revolutions the tire will make in its lifetime.

    asked by christina on January 13, 2011
  8. Math

    Would someone like to help me with these questions? Steps appreciated~ 1. If the diameter of a monster truck tire is 3.5 m and it makes one rotation every 5 seconds, how far does the tire roll in 1 minute?

    asked by Melinda on January 19, 2012
  9. Geometry check my answer?

    The diameter of a car tire is approximately 0.6meters. The warranty is good for 70,000 km. About how many revolutions will the tire make before the warranty is up? More than a million? a billion? ----------------------- my work

    asked by Skye on January 23, 2011
  10. Precalculus

    Please help...a computerized spin balance machine rotates a 25 inch diameter tire at 480 revolutions per minute. (a) find the road speed in miles per hour at which the tire is being balanced (b) at what rate should the spin

    asked by Michelle on September 13, 2012

More Similar Questions