Eric, Chris and I may have hit on a way to do the friction lab with reproducible results -- it worked pretty well today with a variety of different sliding objects. The basic idea was to slide a block on a flat track and let it go, and use the ultrasonic position sensor to measure its velocity decreasing with time after you let go. The slope of v(t) should give you (mu)*g. We tried it with aluminum and wood blocks today of various sizes, and it was fairly reproducible. If we continue to have good luck, it might be a good alternative to the varying the angle of an inclined plane -- kinetic friction seems more reliable than static, and doing a slope measurement averages out a lot of the uncertainty. We'll see if it continues to give reliable results ...
One objection might be that we are measuring kinetic instead of static friction, but myself I don't see this as a big problem.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment