\
Relation between linear speed
of an object and angular speed
of the object is
, where
is the radius of the circular motion and
is measured in radians per unit time.
\
Diameter of the wheel is
inches.
Radius of the wheel is
inches.
Conversion :
\1 mile = 63360 inches.
\1 hour = 60 minutes.
\1 minute = 60 seconds.
\Convert units from inches to miles :
\
\
Number of revolutions
.

Convert minutes into hours :
\
.
Angular speed of a wheel :
.
.
Consider
.
Substitute he values of
and
in above formula.

Thus, the speed of the road is 37.13 mile/hour.
\\
Find how many revolutions per minute should the balancer be set to test a road speed of 80 miles per hour.
\
.
The speed of the road is 37.13 mile/hour.
\The number of revolutions per minute should be 1034.3.