# Need Help Defeating Prof

1. Jun 27, 2007

### turbotrip

Well heres the deal, i kinda have this rivalry going on with this one engineering proff so naturally i took on a challenge from him that i couldnt find the answer to this problem. I dont have to understand it or be able to solve it even (because its a lot more advanced then our class), but I just need a correct solution to show him and he will admit defeat. So for all of you out there who have ever wanted to get back at your professors, please help me defeat mine LOL :tongue:

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2. Jun 27, 2007

### Integral

Staff Emeritus
Unfortunatly for you, the rules of our fourms state that you need to show that you have made some effort to solve the problem. We do not post complete solutions.

3. Jun 27, 2007

### turbotrip

oh man this stuff is pretty tough, but ill give it a try:

Fmax = (static) * (normal force)
That should give you your maximum in the static friction condition

(linear acceleration) = Mu(kinetic) * N
F=ma will give you acceleration

Static friction x radius = torque
torque / angular moment = angular acceleration
angular acceleration x radius = linear acceleration
static friction + ma should be your total force

For the second part, since it breaks static friction, angular acceleration is no longer related to linear acceleration

and thats about as far as i got

Last edited: Jun 27, 2007
4. Jun 27, 2007

### Astronuc

Staff Emeritus
This might be useful
http://hyperphysics.phy-astr.gsu.edu/hbase/mi.html

No slip implies the radial velocity of the surface of the disc is equal in magnitude to the linear velocity of the cm of the disc.

There is the force associated with translation as well as rotation.