AP Power and Energy 2 items

1) Some folks are still missing the point: power is the rate of transfer or transformation of energy. It does not have to go into changing Ek. When a car is accelerating up hill, power from the engine is going into raising EP, EK, and combating friction and air resistance ( changing Eth and overcoming losses to outside the car - call these losses to outside a negative Qin) all at the same time. These are all the things that can comprise work and power is just the rate at which work is done.

Mav is only the rate of change in Ek. Mav usually = Fnet v, but power from a force involves the total of that force, not just what is left over after subtracting the forces opposed to it. If you don't believe me run up 100 flights of stairs at a constant speed (Mav =0) and let me know how little power it and work it took. The power supplied by a particular force may usually be found from multiplying that force by the velocity in the direction of that force, but this not fool proof. Consider two train engines or bulldozers (or Sumo wrestlers for that matter) of different powers pushing in opposing directions. The engine that is overpowered is exerting a force opposite the velocity but it is not putting out negative power. Its power is going into friction or tearing up the earth or ripping apart metal. The work kinetic energy theorem is incomplete at best and downright misleading often.

2) AP Section 2 tests - I am the nameless committer of the error. Thus the need for reclaiming your tests. Put them in the test folder Monday.