PHYS 2101 Lecture : Lecture 11
Document Summary
Announcements feb. 8, 2012 wednesday (10th: hw #4 is already posted longer . If you didn"t get your test yet, pick it up now or at the end: quiz . 8 conservation of total energy (emech versus etot) > next week, chap 10 (center of mass, linear momentum, collisions) Chapter 9: center of mass & linear momentum. Up to now, we"ve taken boxes, balls, pigs, penguins to be particles. We know how apply newton"s laws to determine dynamics of a point particle. Now we have a real mass (system of individual particles). How do we do this: we nd the center of mass (com) : A point that moves as though all mass of a system were concentrated at that point (doesn"t have to be on the object) How to determine com ? (center of mass) Experimentally: find the point where it balances (as if all external forces are applied there) + m 2 m1(0) + m 2 (0) m1.
