A wheel has a 12 inch radius rotating at 620 RPM. What is the speed of the car in MPH?

circumference = 24π inches

so speed = 24π(620) inches/min
= 14880π/(12(5280)) miles/min
= 14880π/(12(5280)) miles/ (1/60) hrs
= 44.27 mph

check my arithmetic

To find the speed of the car in miles per hour (MPH), we need to use the given information about the wheel and its rotation speed.

First, let's calculate the circumference of the wheel. The circumference of a circle is given by the formula:

C = 2πr

Where C represents the circumference, π is a mathematical constant approximately equal to 3.14159, and r is the radius of the wheel.

In this case, the radius of the wheel is given as 12 inches. Substituting this value into the formula:

C = 2π(12)
C ≈ 75.398 inches

Now, let's convert the rotation speed of the wheel from revolutions per minute (RPM) to inches per minute. Since each revolution covers the circumference of the wheel, the distance traveled per minute is equal to the circumference multiplied by the number of revolutions per minute:

Distance traveled per minute = C * 620 inches

Next, we need to convert the distance traveled from inches to miles. There are 12 inches in 1 foot, and 5280 feet in 1 mile, so:

Distance traveled per minute in miles = (C * 620) / (12 * 5280) miles

Finally, to find the speed of the car in miles per hour, we multiply the distance traveled in miles per minute by 60 (to convert from minutes to hours):

Speed in MPH = (Distance traveled per minute in miles) * 60

Let's calculate the value.