Newton's Laws Applications

Question

Semi-trailer trucks have an odometer on one hub of a trailer wheel. The hub is weighted so that it does not rotate, but it contains gears to count the number of wheel revolutions—it then calculates the distance traveled. If the wheel has a 1.17 m diameter and goes through 290,000 rotations, how many kilometers should the odometer read? (Enter a number.)

 __km

Answer 1

Hey John,

This question actually just comes down to geometry.

1. We know how many rotations the wheel goes through, so we just need to find how far the car will travel in one rotation
2. One rotation = the circumference of the tire
3. C = 2Πr = Πd = Π*1.17m
4. Now just multiply that circumference by 290,000 to find out the distance the truck travels
5. Don't forget to convert from m to km -- divide by 1000.