Posted by **Gabi** on Wednesday, May 11, 2011 at 12:30am.

The speedometer of John's truck uses the revolutions of his tires to calculate the speed of the truck.

How many revolutions per minute do the tires make when the truck is traveling at 55 miles per hour?

(picture with tires with diameter of 26 in.)

Suppose John buys tires with a diametr of 30 inches. When the speedometer reads 55 miles per hour, the tires would still revolve at the same rate as before. However, with the new tires, the truck travels a different distance in each revolution. Calculate the actual speed when the speedometer reads 55 miles per hour.

Thank you so much.

- Math -
**PsyDAG**, Wednesday, May 11, 2011 at 12:58pm
Circumference = π diameter = 3.14 * 26

55 mph = 4,840 feet/hr = 4,840 * 12 inches/hour = 4,840*12inches/60 minutes

Divide the above answer by circumference to get revolutions/minute

Use the above process to get the answer to your second question.

## Answer this Question

## Related Questions

Physics. - A monster truck has tires with a diameter of 1.10 m and is traveling ...

math - 72 tires are changed between a small and large truck over 8 weeks. The ...

3rd grade math - A 16 wheler truck has 16 tires. The cab of a 16 wheeler has 6 ...

Precalc - Hello I need help with this question. I know that the formula for ...

physics - Rubber tires and wet blacktop have a coefficient of kinetic friction ...

Math - A truck with 40-in.-diameter wheels is traveling at 50 mi/h. a) Find the ...

Trigonometry - The tires on a car have radius 14 inches. Find the angular speed ...

physics - A construction worker riding in the tray of a truck traveling at 10 m/...

physics - A truck of mass 8912 kg moving at a speed of 66.7 mph has lost its ...

Physics - A truck of mass 9212 kg moving at a speed of 73.2 mph has lost its ...