CPM Homework Help : INT2 Problem 9-123

Jill’s car tires are spinning at a rate of $120$ revolutions per minute. If her car tires’ radii are each $14$ inches, how far does she travel in $5$ minutes?

$140π$ in

$8400π$ in

$3360π$ in

$16800π$ in

Hint:

Circumference $= 2$ * $π$ * diameter 'revolution'.
In this case, our diameter is $14$ inches.
We also know we have $120$ revolutions per minute, with $5$ minutes given.

Answer:

By using dimensional analysis, we see that the circumference multiplied by the
total revolutions gives us $16800π$ inches. The answer is D.