Register to reply

Rotating Bicycle Wheel

by kiwikahuna
Tags: bicycle, rotating, wheel
Share this thread:
kiwikahuna
#1
Jun26-07, 11:51 PM
P: 61
1. The problem statement, all variables and given/known data
A professor holds a bicycle wheel rotating at 402 rev/min by a string attached to a weightless axle 20 cm from the wheel. The acceleration of gravity is 9.8 m/s^2. If all 7.5 kg of the wheel can be considered to be at its 53.6 cm radius, at what frequency in rpm does it precess?


2. Relevant equations



3. The attempt at a solution
Frequency=omega
I honestly am stumped with this problem but I was thinking of using a rotational kinematics equation to solve this.
The 402 rev/min can be converted to Omega initial. We can solved for Omega final using wf^2=wi^2 +2a(delta x).
Please help if you can!
Phys.Org News Partner Science news on Phys.org
Hoverbike drone project for air transport takes off
Earlier Stone Age artifacts found in Northern Cape of South Africa
Study reveals new characteristics of complex oxide surfaces
Astronuc
#2
Jun27-07, 06:18 AM
Admin
Astronuc's Avatar
P: 21,808
Perhaps this will help.

http://hyperphysics.phy-astr.gsu.edu/hbase/rotv2.html

If all 7.5 kg (the mass) of the wheel can be considered to be at its 53.6 cm radius, . . .
What is the moment of inertia I for a ring/hoop.
http://hyperphysics.phy-astr.gsu.edu/hbase/mi.html#cmi

see also http://hyperphysics.phy-astr.gsu.edu/hbase/mi.html
kiwikahuna
#3
Jun27-07, 07:11 PM
P: 61
Ok here's what I did.

(Mass of the wheel) * (Radius of the wheel)^2 (Omega given) - (Mass of the wheel)* (Length of the string)^2 * (Omega Unknown) = 0

(7.5 kg)(.536 m)^2(402 rev/min) - (7.5 kg) *(0.20 m)^2 * (Omega unknown) = 0

Is this the right to solve this problem? I feel as if I'm not getting/missing something.


Register to reply

Related Discussions
Variable diameter bicycle wheel Classical Physics 3
Gyroscope/bicycle wheel question Classical Physics 7
Spinning bicycle wheel Introductory Physics Homework 1
Rotating Wheel Problem Introductory Physics Homework 1
Rotating wheel question Introductory Physics Homework 4