Recent content by Kimball Clark

It's pretty simple, according to the lab manual I inherited, the students are to try to measure the coefficient of friction of a wood block first on a horizontal table top covered with paper. They drag the block across the table with about 5 different mass loads added: the mass loads range from...

Thank you. That is a very interesting video. I have no idea why it happens either but that is the behavior I have been seeing in my friction labs for years.

That is a very good question. I use some standard weight sets that have been around for a long time. I have also placed different amounts of weight on a short piece of a 2" x 4" pine. I have tried covering the ramp with white postal wrapping paper. It might be worth it to invest in some small...

I suppose I reacted a bit hastily. The reference you listed gives a the standard Coulomb theory for dry friction. What I would like to find is either some corroboration of what I and my students see with some kind of explanation or something that defines parameters needed for the Coulomb...

Well like I said I and my students have been doing the labs for a long time. And what we see is that larger masses slide down faster. Does that agree with any theory you know of Coulomb or otherwise. Keep in mind that I'm talking about very low speeds. I assumed that since I said I had been...

I have been teaching Physics at the introductory level now for over 30 years. In that time I have taught a lot of labs on friction. Using the small masses readily available in the lab and using motion detectors to measure the velocity of the objects neither I nor any of my students has ever...