Rotational Motion

Honors Physics continued on today with their study of rotational dynamics with an overview of moment of inertia and rotational equilibrium. Moment of inertia stands in for mass in rotational systems - mass distribution is very important for extended objects and their overall motion. For equilibrium, we had to add on a new condition - an object in complete equilibrium must be subject to both zero net force and zero net torque. So, an object can be in translational equilibrium, rotational equilibrium, both or neither. The problem set you have tonight assumes complete equilibrium and uses that scenario to have you determine the magnitude of forces. The solutions are on Edline and here's another link for you to use.

Physics B and Physics F completed their circular motion labs. No one got a black eye from getting whacked with a rubber stopper, so it was a great success. We'll talk about the lab tomorrow before heading into rotational dynamics.

Physical Science completed their two simple machine experiments. The inclined plane reduces your effort force by providing more distance through which to put the force. The first and second class levers do the same thing. Third class levers make you put in more force than the machine gives out, but that is good if you need to do some delicate work (like with computer circuitry) or if you need an increase of distance, instead. Tomorrow, we'll use the labs to help introduce our unit on work, power and simple machines.

Homework

Honors Physics - Practice 8B #2, 3 and 4
Physics B and F: Complete Centripetal Force and Speed lab write up
Physical Science: Complete Inclined Plane and Levers lab write up