Recent content by ezfzx

You mean like this? I found this online 7 years ago.

I cannot help you with the specifics of your physics research, but I can give you some general advice that I give my students. Do not lock into one specialization, especially a topic studied by only a few highly-competitive people on Earth. You may be able to get into a program and become the...

This sounds interesting, but (speaking only for myself) I'm not clear on the goal. You want to see the affect of nearby vegetation on the water level of the bog. But that is a big wide open problem statement, that probably needs to be refined a LOT. When you say "water level", do you mean...

Yes, I suppose I'm surprised by how many people in this forum have NOT seen this effect ... a decade or so ago, these kind of pictures were all over the place ... some REALLY extreme effects were common. And now it's like these pictures have just vanished from the Internet. It's a bit like...

Yeah, I've watched these folks put this stuff down, and I'm certain they try their best to make sure that it's all evenly supported underneath. But over the course of 1000s, if not millions of miles of road, there's bound to be some goof spots where the ground has settled leaving gaps, etc. And...

Doesn't really look like improperly applied tape. Looks more like improperly applied road. :)

OK, my wife got tired of me talking about this, so she took this picture a few miles from our house. Generally, these kinds of shots better when you're looking down the length of the line, but this is still pretty good. https://www.physicsforums.com/attachments/275044 There were some I saw a...

Perhaps, but quality asphalt doesn't do this. But it also happens with brick roads that have a loose foundation. Here's a pic of the same phenomenon scanned in from the 12th edition "Conceptual Physics" textbook by Paul Hewitt: This one is good, but not as dramatic as the cross-walk lines. I'm...

Well, the image I was looking for showed a distinct bend in the lines. When the power tires are on or just behind the line, as the vehicle accelerates from stationary, it pulls the low-grade asphalt back. Over time, the line painted on the asphalt gets pulls WAY back. I imagine it's very...

We've all seen these photos of the crosswalk (or other street lines) on the asphalt distorted when the driven tires of cars push back as they roll forward. (At least I'd like to think we've all seen them.) I used to have one I took myself a long time ago. But, for the life of me, I can't seem to...

I was actually modelling it as a 2D problem. And we cannot ignore friction. If the goal is to produce a simulation that looks like the real thing, friction is essential. The only unrealistic part is the assumption that it rolls without slipping. But I'm sure that if I can get a solution to...

Well, interesting, but I think there was a misunderstanding. In order to work on the "ball rolling inside cylinder which is rolling down an incline" problem, sometimes it helps to step back to a similar simpler problems. So, instead of a ball, we have a solid cylinder, and instead of the...

OK, so how does this compare to a cylinder rolling on a moving conveyor belt? Under what conditions is the cylinder moving toward or away from the direction the belt is moving, or is it rolling in place?

I'm sure there is too ... but what's the fun in that? So I guess a diff.eqn. is too difficult?