Calculating the Force on a Bicycle Wheel

In summary, the problem involves a bicycle wheel with a radius of 32.0 cm and a mass of 1.82 kg, a resistive force of 137 N applied to the rim, and a force applied to the sprocket at different radii resulting in an angular acceleration of 4.50 rad/s^2. The task is to find the force, F, at two different sprocket radii and the combined mass of the bicycle and rider. To solve this problem, the use of tangential acceleration, kinetic energy, and moment of inertia for a shell are necessary. However, it may be easier to approach the problem using forces and torque.
  • #1
BrettF
5
0
I have been trying this problem for a while and can't seem to figure it out:

A bicycle wheel has a radius R = 32.0 cm and a mass M = 1.82 kg which you may assume to be concentrated on the outside radius. A resistive force f = 137 N (due to the ground) is applied to the rim of the tire. A force F is applied to the sprocket at radius r such that the wheel has an angular acceleration of 4.50 rad/s^2. The tire does not slip.

a. If the sprocket radius is 4.53 cm, what is the force, F (in Newtons)?
b. If the sprocket radius is 2.88 cm, what is the force, F?
c. What is the combined mass (kg) of the bicycle and rider?

I know that the tangential acceleration a = rα where α is rotational acceleration.
I also know the Kinetic energy must be K = ½ Iω^2+ ½Mv^2 where the first term is the rotational kinetic energy and the second term is the translational kinetic energy.
Finally, I know that I which is the moment of inertia for a shell (the shape of the bicycle) is Mass*Radius^2.
I've been doing the algebra with it and can't seem to get any meaningful results. Am I on the right track with this thinking? Thanks in advance for the help.
 
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  • #2
BrettF said:
I've been doing the algebra with it and can't seem to get any meaningful results.
Please show what you did (that's the point of the homework template - please do not delete it).

Working with energy is possible, but using forces and torque everywhere is probably easier.
 
  • #3
The linear KE cannot be interesting because you do not know the mass of the bicycle. Concentrate on torques and angular acceleration.
 
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FAQ: Calculating the Force on a Bicycle Wheel

What is the formula for calculating the force on a bicycle wheel?

The formula for calculating the force on a bicycle wheel is F = m x a, where F is the force in Newtons, m is the mass of the wheel in kilograms, and a is the acceleration in meters per second squared.

How do you determine the mass of a bicycle wheel?

You can determine the mass of a bicycle wheel by using a scale or balance to weigh the wheel. Make sure to include the weight of any tires or other components attached to the wheel in your measurement.

What is the acceleration of a bicycle wheel?

The acceleration of a bicycle wheel can vary depending on factors such as the slope of the road, the rider's pedaling force, and the resistance of the wheel. However, on a level surface, the acceleration is typically around 9.8 meters per second squared due to the force of gravity.

How does the force on a bicycle wheel affect its speed?

The force on a bicycle wheel directly affects its speed, as described by Newton's Second Law of Motion (F = m x a). The greater the force applied to the wheel, the greater its acceleration and thus the faster its speed will be.

Are there any other factors that can affect the force on a bicycle wheel?

Yes, in addition to the mass and acceleration of the wheel, other factors such as air resistance, rolling resistance, and friction can also affect the force on a bicycle wheel. These forces can impact the overall speed and efficiency of the bicycle.

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