Precalc
posted by Xochil on .
A car is moving at the rate of 60 miles per hour, and the diameter of its wheels is 2.5 feet (1 mile=5280 feet)
a) Find the angular speed of the wheels in radians per minute
b) Find the number of revolutions per minute the wheels are rotating.

I shouldve known better than to actually think i was gunna get help...

V = linear speed
r = radius
omega = angular velocity
RPM = Revolutions per minute
r = diameter / 2
60 mph = 60 * 5280 ft
V = r * omega
60 * 5280 = ( 2.5 / 2 ) * omega
316,800 = 1.25 omega Divide both sides ba 1,25
316,800 / 1.25 = omega
253,440 = omega
omega = 253,440 radians / h Divide both sides by 60
omega = 253,440/ 60
omega = 4,224 radians / min
1 rotation = 2 pi radians
RPM = 4,224 / 2 pi
RPM = 2112/ pi
RPM = 2112 / 3.1416
RPM = 672.2689 rotation / min