related to physics
2007-07-17 05:00:54 · 3 answers · asked by ayesha 1 in Science & Mathematics ➔ Physics
Sorry, but I think answer 1 is a washout. You can demonstrate both uniform circular motion and friction, and how to measure the coefficient of friction, if you show how a penny slides off a rotating turntable (the kind for LP records and 45s, if you can find one). To get the penny to slide you may need the turntable to run at 45 rpm (or 78 if it has that speed) and maybe put on a 12-inch record to serve as the turntable's surface. You want a smooth surface. The penny has to slide off if it's placed on the edge or the demo can't be done. If it does, then you can move it nearer the center until it stays put. Then you can find the radius where it just barely stays put and calculate the coefficient of the friction between the penny and the turntable surface. At this radius r, omega^2*r = g*mu, where omega is the turntable's rotation rate in rad/sec and mu is the coefficient of friction. You can calculate omega as 2*pi*rpm/60.
2007-07-20 15:39:30 · answer #1 · answered by kirchwey 7 · 0⤊ 0⤋
The radial acceleration = v² / r a = (5.2)² / .4 = 67.6 m/s² =================== Hence the answer closes to (b) 68 m/s² ==============================
2016-05-20 02:48:16 · answer #2 · answered by ? 3 · 0⤊ 0⤋
http://answers.yahoo.com/question/index;_ylt=Aq.r7A8rTK.FoA0NPwZi5_Dsy6IX?qid=20070510084431AArjVzi
2007-07-17 07:05:48 · answer #3 · answered by Anonymous · 0⤊ 1⤋