I need help I am stuck on this problem any help will be useful

Question

A truck with 38-in.-diameter wheels is traveling at 50 mi/h.

Find the angular speed of the wheels in rad/min, *hint convert miles to inches & hours to minutes:   ___ rad/min

How many revolutions per minute do the wheels make?    __rpm

Round your answers to 1 decimal place.

Answer 1

1 mile = 5280 feet = 5280 x 12 inches = 63360 inches

1 hour = 60 minutes

So a point on the wheel is moving a distance (50 x 63360) / 60 inches per minute

Circumference of wheel = 2 x pi x 38

So wheel makes [(50 x 63360) / 60] / (2 x pi x 38) revolutions per minute

To convert this to radians per minute multiply this by 2 pi, giving [(50 x 63360)/60) ] / 38 rad/min

1389.473 radians per minute, which is 1389.5 to 1 decimal place