trigonometry
posted by monic .
A truck with 48in.diameter wheels is traveling at 45 mi/h.
(a) Find the angular speed of the wheels in rad/min.
rad/min
(b) How many revolutions per minute do the wheels make?
rev/min

one rotation = 2π(48) = 96π inches
in 1 hour it goes 45 miles
= 45x5280x12 inches
= 2851200 inches
number of rotations per hour
= 2851200/(96π) = 9453.8.. rotations per hour
= 157.563 rpm
= 157.563x(2π) radians /min
= 990 radians/min 
45 mi/hr * 5280*12 in/mi /(2pi*48in/rev) * hr/60min * 2pi rad/rev = 3960 rev/min
rev/min = rad/min * rev/2pi rad, so divide 3960 by 2pi 
Oops. Off by a factor of 2. I was using a radius of 48 in

Rats, I read it wrong also
radius should have been 24 , not 48
make the necessary adjustments in the above.
(time to go to bed)
Respond to this Question
Similar Questions

L PreCal
A car is moving at a rate of 65 miles per housr and the diameter of it's wheels is 2.5ft. Find the number of revolutions per minute the wheels are rotating. I have no idea where to begin on this question. How do you find rev per min? 
Physics
A flywheel with a diameter of 2.45 m is rotating at an angular speed of 74.1 rev/min. (a) What is the angular speed of the flywheel in radians per second? 
physics
What is the angular speed in rev/min of the Earth as it orbits around the sun? 
Precalc
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 … 
Trignometry
A car is moving at a rate of 55 mph and the diameter of its wheels is 2 feet. A) Find the number of revolutions per minute the wheels are rotating. B) Find the angular speed of the wheels in radians per minutes. 
trigonometry
A truck with 48in.diameter wheels is traveling at 55 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? 
Math
A truck with 40in.diameter wheels is traveling at 50 mi/h. a) Find the angular speed of the wheels in rad/min b) How many revolutions per minute do the wheels make? 
Math
A truck with 36in.diameter wheels is traveling at 55 mi/h. Find the angular speed of the wheels in rad/min, *hint convert miles to inches & hours to minutes How many revolutions per minute do the wheels make? 
Trigonometry
a bicycle with 24inch diameter wheels is traveling at 15mi/hr. a) Find the angular speed of the wheels in rad/min. b)How many revolutions per minute do the wheels make? 
algebra
A car is moving at the rate of 80km/h. the diameter of its wheel is 60cm. a, find the number of revolutions per minute that the wheels are rotating. b, find the angular speed of the wheels in radians per second.