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 1.19 m diameter and goes through 120,000 rotations, how many kilometers should the odometer read?

Answer 1

Are you cheating young man?

Answer 2

Hello

1) First, we calculate the circumference of the wheel. Since the diameter is $d=1.19~m$, the circumference is
$c=\pi d=3.74~m$

2) The total distance traveled by the wheel and the truck will be the product between the circumference of the wheel and the number of rotations:
$d=cN=3.74~m \cdot 120000 = 448392~m=448.4~km$