Alright folks, I'm a junior in persuit of an ME degree, I've got a Linear Systems test tomorrow and there is one type of problem that absolutely has me stumped. Our prof is out of town today so I couldn't ask him about this stuff, and none of my classmates really know how to do it...

So here goes... The pic is currently waiting for approval and then I can paste it into the thread

I'm more interested in equation stuff, because we can't use calculators, but lets say for simplicity that initially:

Wo=10 rad/s
Vo=0 m/s
Ms=.5 (coefficient of static friction)
Mk=.4
J=.375 kgm^2
Theta-30*
m=3 kg
r (radius of wheel) = .5m

f=force of friction, pointing in same direction as Vo

OK, so here's what we've got so far: This is going to be tough conveying symbols, but here goes...

Sum of moments about 0=J <alpha>, so J<alpha>= fr = m g cos(theta) r
sum of forces in x direction = ma, so ma=f-mgsin(theta) = mgcos(theta)-mgsin(theta)

From here I don't really know where to go. I know we are supposed to use these equations and make a differential equation to solve for when the wheel stops slipping at time (t), then solve for how far up the ramp it goes before velocity = 0.

I know that this is probably really confusing the way I've written it, but any help is definitely appreciated!!!

 

That actually sound like a pain the way you have it written. Can you PM me the photo or a link to it so I can really see the problem. I have not done any physics for a few years but I think that I remember the problem that you are talking about. If not I will definately let you know so others can give a crack at it.

 

06, it should be a bit more clear once the image is approved, then I'll post it in the thread. Basically, there is a wheel on an incline that is rotating but has no translational motion. Using the info above, we have to figure out when the wheel will stop moving up the incline plane. To do that we have to figure out using a differential equation, when the wheel stops slipping on the plane and the translational motion is directly proportional to the rotational motion.

I'm pretty desparate right now, so I thought I would at least try on here... I know it's a big pain since you can't use any symbols...

 

I don't think my Physics 101 class I am in is gonna help ya out a bit Best of luck!

 

Ok, I think you have me stumped also. I have never had a physics class but I always helped my roomate with his since some say that I have a very mechanical mind. I don't think so but who knows. Let me see the picture and I will see what I can do, don't hold your breath though.

 

Ok, here's the pic.

[IMG][/IMG]

 

Ok, I am lost. Sorry but it has been too long and too many beers since the last time I did one of those.

 

No worries, I understand! I appreciate the concern though. I think I might be coming up with something, but we'll see...

 

and this ladies and gentleman is why i am a fireman and not a college boy! that and i liked the beer and girls to much (3 years and maybe 20 something hrs...hahaha i got A's in the classes i went to!)

brett

oh yeah...good luck

 

Heck, that's an easy one ..... the answer is "Yes, the plane will fly".




Sorry, never been any good with physics.

PISTOL

 

Sorry man I bin to long outta the loop to give you a hand with physics.


Nick

 

Haha, I needed the beers to get though it!

 

Well, I've found when the wheel stops slipping, now I just need to figure out when it stops traveling up the ramp...

 

Let me chew on this a bit and get back to you.

**Busts out TI-89 and blows off dust**

 

**Gladiator music begins to play softly and becomes louder as HOHN travels back to his desk as he wields his trusty TI-89 in hand **

Let the games begin