Recent content by whitejac

Homework Statement Homework Equations This would be the part I think I'm missing The Attempt at a Solution In the fourth line, Ix, where is the justification for multiplying 1/3 by the first term? I believe they are using the center of inertia of a rod, which is mr2 and the first term...

Mechanical Engineering Undergrad here: So this didn't seem explicitly like a homework question, but I was wondering how to describe a solar cell in terms of thermodynamics. If I had to model it with the first law of thermodynamics, I would consider it a simple loop of heat/work exchange...

Looking at it again. I'm sorry. I think my problem was just misreading the answer. Value a just the value used to reference the length? (6in) This would make: F spring = xk x = aθ Thus a(kaΘ) = M And it's negative because the fbd assumes the weight is tending CW while the weight and the...

Homework Statement Homework Equations The equations are all given The Attempt at a Solution This isn't really a homework question... it's solved, but I'm having a hard time following it. I don't understand where the first term: -a(kaθ) comes from. I can see it's the moment relation...

I've finally figured it out! I have to say, I am embarrassed how much I forgot of my multivariable calculator class. I thought I understood it better than this, but I suppose application is the real challenge. Thank you so much for your patience. I will post back Sunday night with my attempt at...

Okay, so I have done most of this but am out of town and away from the computer unail Sunday night. I have rearranged Tm into an expression that has αL. Considering what you said about Radius R being the thing that changes the angular acceleration here, I took the derivative with respect to R...

I've never heard of SUVAT, but this is what you mean? Integrating theta twice would yield the second equation regardless. Okay, a load accelerating from rest at αL would have the position equation: θL = θ0L+ω0Lt+1/2αLt2 when θL =θL/2 and I.C.'s are applied: θL = αLt2 And t = SQRT[θL/αL]

I simply don't know.

I know it doesn't, that's why taking derivatives isn't something I can currently do. I don't know where to put the t because it seems like I'd just be placing it arbitrarily. R isn't related to time as the pulley isn't growing or shrinking with relation to time. The Radius reduces the...

I'm running out of variables here. The only other one not given is αm, which is something I currently do not know how to find specifically.

Reduction in R reduces the length, thus the amount of time.

Well, in that case I would set R to the minimum it could go. Using the expression I would... set R to zero? That doesn't make sense.

How would this look? From what my professor has told me, you set the torque to its max so that your arm/pulley/etc uses the minimum amount of time (though you'd factor in some safety in a real application because it's highly idealized)

I've been working on this most of the day between work. Here's what I've come after studying some notes my professor put out and trying do it. This relates the torque with the two pulleys in terms of J and alpha. His notes have a dynamic expression for belt driven pulleys with a rotating base...

okay, but you said here: So I'm a bit confused as to where the distinction lies and how to see it in the future.