# Rotating wheel

1. Sep 10, 2009

### physicsnoob1

1. The problem statement, all variables and given/known data
A wheel of radius r is rolling along a muddy road with speed v, and particles of mud are being continuously thrown off from all points of the wheel. ignoring air resistance, what is the trajectory of a mud glob thrown off the wheel when it is at angle (theta) to the horizontal? at what (theta) is the height maximized? What is the meaning of the critical speed v^2 = rg?

2. Relevant equations

v = 2(pi)r / T is the propagation velocity of the wheel. but my first question is, is this the same as the rotational velocity? i've thought about it for a while and it seems like it is. i am stumped as to how to find the trajectory of the mud glob though. please help!

3. The attempt at a solution
well i guess im still stuck on figuring out if the propagation velocity is the same as the rotational velocity. after that i was thinking about playing with the velocity vectors to find an expression for the trajectory. the only force acting on the glob should be gravity i think.

Last edited: Sep 10, 2009
2. Sep 11, 2009

### Hootenanny

Staff Emeritus
Welcome to Physics Forums.

Have you tried to sketch the problem? You know that when the wheel is at some angle, theta, a mud particle flies off. In what direction relative to the wheel will the particle travel?

3. Dec 19, 2010

### Richyfeller

Please help me to show that, if v^2=gr, no mud can be thrown higher than r+v^2/2g+gr^2/2v^2 above the ground,

Last edited: Dec 19, 2010
4. Dec 19, 2010

### Richyfeller

yes i sketch the problem, but the equations to use for the proof is my problem

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