Physics 11-15-11 Intro to Work

PHYSICS: Funny thing about words, all this work you thought you’d been doing, was it? Work, I mean? Great intro to chapter 5! Jakin, I think you almost did move the lab station! 🙂 And I think you’ll all do great with the work problems, just remember everything from the last chapter and multiply by d!

BTW – Did you figure out what to do with the conveyer belt problem from the end of class? Why were you supposed to subtract?

Physics 10-28-11 Friction & Normal Force (& Zorba!)

PHYSICS: So why don’t things that are moving just keep moving? Here’s the intro lecture on friction. Remember a few key things. Net forces produce acceleration. You can find Ff a couple of different ways – it’ll be part of a net force equation and can be found from the coefficient of friction equation. If and ONLY if your object is moving at a constant velocity, Ff will equal Fa. Fn is only sometimes equal to Fw. If your object is pulled at any angle (or pushed), Fn will be a part of Fnet in the vertical direction. Is that enough for now? Have a great weekend!!

BTW – Did you figure out Zorba? The solution is at the beginning of this vodcast.

flickr photo by kbaird

Physics 10-26-11 Newton’s 2nd & 3rd Laws

PHYSICS: So an object at rest can be at equilibrium, but what about an object that is moving? And how does equilibrium relate to Newton’s first law? Or Newton’s second law? And what if you don’t have balanced forces. Here’s the lecture from Wednesday on just that! Now remind me, net forces produce what?