







The angular speed of a wheel 
20200903 

From Catrina: A car is moving at a rate of 75 miles per hour, and the diameter of its wheels is 2.6 in. Find the angular speed of the wheels in radians per minute. Answered by Penny Nom. 





Angular velocity 
20181205 

From Kolade: Krusty the Clown and Sideshow Bob have covered themselves in velcro, and shot themselves out of a large
cannon so that they stick to a huge rotating velcro wheel (don’t try this at home). As shown in Figure 1(a),
Krusty is now stuck to a point 3.00 m from the center of the wheel while Bob is stuck to another point 5.00 m
from the center. The wheel is rotating counterclockwise at 10.0 rpm. Conveniently a set of axes is suspended
just in front the wheel (Krusty asked for axes, like the ones you would use to chop wood, so that he and Bob
could chase each other with them in the usual wholesome entertainment he is known for. Unfortunately, the
set designer misunderstood.) The axes do not rotate with the wheel.
(a) Find Krusty’s and Bob’s angular velocities, in radians per second. Answered by Penny Nom. 





Angular speed 
20181018 

From Akidima: A bicycle wheel rotates uniformly through 2.0 revolutions in 4.0 seconds .
What is the average angular speed of the wheel Answered by Penny Nom. 





Angular speed 
20170121 

From Kenzi: A wheel of radius 14 inches is rotating 45°/sec. What is the linear speed in in/sec and the
angular speed in RPM? (Round your answers to three decimal places)
I already found the linear speed. I got 10.996 in/sec. I don't know how to find the angular
speed. Answered by Penny Nom. 





Revolutions per minute 
20141024 

From Edward: Hello; I have a 28.2 inch diameter tire; do not worry about engine RPM or gear ratios, please tell me what the RPM
of that tire is at 8 MPH and 64 MPH. Thank you.
Sincerely; Edward Answered by Penny Nom. 





Angular speed 
20140629 

From andrea: a wheel having a radius of 10cm rotates such that the linear speed at its rim is 30mls.
what is the angular speed of the wheel in rpm? Answered by Penny Nom. 





Revolutions per second 
20121018 

From Crystal: Suppose a car wheel is 26 inches in diameter.
a) If the tire completes one rotation, how far would the car travel?
b) If the car is traveling at 60 miles per hour, how fast is the car wheel spinning in revolutions per second? Answered by Penny Nom. 





Angular speed 
20101212 

From Jason: 7 in. pulley traveling @ 175ft/sec. What is the rpm? Answered by Stephen La Rocque and Penny Nom. 





Angular speed 
20101203 

From Julie: If the angular speed of a circle is 360 degrees divided by the time it took to rotate,
how do I calculate ones that have greater rotations than the amount of time?
I mean, you calculate the angular speed of a merrygoaround that spins once every 5 seconds
by doing 360degrees/5 sec, but how do you calculate a merrygoaround that has 16 rotations every 4 seconds? Answered by Penny Nom. 





Angular speed 
20091119 

From Atalie: The engine of a sports car rotates at 5000 revolution per minute. Calculate the angular speed of the engine in radians per second, given that 2pi radians = 1 revolution Answered by Robert Dawson. 





Angular speed 
20090804 

From Mary: The engine of a sports car rotates at 5000 revolutions per minute (rpm). Calculate the angular speed of the engine in radians per second. Use 2 radians = 1 revolution. Answered by Penny Nom. 





Angular & Linear Speed from a Sine Graph 
20080819 

From Kim: Kim, a student:
I am given a graph with a wave. The amplitude is 5cm and the period is 4cm. I am suppose to find the angular speed. What I need to know is the formula for angular speed and how do I use these numbers to get the correct answer. Answered by Janice Cotcher. 





The current in a river 
20080612 

From Joi: To approximate the speed of the current of a river, a circular paddle wheel with radius 4 feet is lowered into the water. If the current causes the wheel to rotate at a speed of 10 revolutions per minute, what is the speed of the current? Express your answer in miles per hour. Answered by Harley Weston. 





Radians 
20080208 

From Brian: I'm teaching Precalculus right now and will be covering the formula to convert angular speed into linear speed. My question is about the units involved. Using v=rw, if r is mearsured in feet and w is measured in radians/second then v is measured in ft/sec. What happened to the units of radians? I can't find a good way to explain why they are not part of units for velocity. Do you have a good explanation?
Thanks, Answered by Stephen La Rocque. 





Radial motion 
20071113 

From abdulai: a circular saw with diameter 18.4cm rotates at 2400rpm. What is the angular speed of a point on the edge of the saw blade in radians per second? Answered by Penny Nom. 





Angular speed 
20070805 

From Virginia: the engine of a sports car rotates at 5,000 revolutions per minute (rpm). calculate the angular speed of the engine in radians per second. use 2n radians = 1 revolution Answered by Stephen La Rocque. 





Angular speed 
20070118 

From Cristina: A car is moving at a rate of 50 miles per hour, and the diameter of its wheels is 2.5 feet. a) Find the number of revolutions per minute the wheels are rotating. b) Find the angular speed of the wheels in radians per minute. Answered by Stephen La Rocque. 





Angular speed 
20070106 

From Robert: A rear wheel and tire on a John Deere 8520 farm tractor has a 39in. radius. Find the angle (in radians) through which a wheel rotates in 12 sec if the tractor is traveling at a speed of 22 mph. Answered by Penny Nom. 





Angular speed 
20061004 

From Jack: A horse on a merrygoround is 7m from the center and travels at a speed of 10km/h. What is its angular speed? Answered by Stephen La Rocque. 





Angular speed 
20040201 

From Rachel: A 4 inch pulley on a motor makes 1500 revolutions/minute. It is connected to an 8 inch saw blade.
a. Find the angular speed of the pulley in radians/minute
b. Find the angular speed of the saw in radians/ minute
Answered by Harley Weston. 

