Thursday, March 17, 2011
Thurs-Day 1
Physics - we reviewed the Doppler Effect, and the Law of Reflection, noting that the angle of incidence is the angle between the original/incident ray and the NORMAL (perpendicular line) drawn from the surface.
We then discussed the meaning of "in phase" and "out of phase" with respect to:
1. two points on a given wave
2. two separate waves.
Two waves that are in phase will have constructive interference throughout.
We then introduced the term "resonance", which occurs when a wave (of energy) produces and in-phase wave in an object that will vibrate at the SAME frequency of the incoming wave, thus producing the maximum constructive interference, i.e. resonance!
We finished up the problems in Waves 4, and then we did a lab in which we measured the speed of sound in air at room temperature.
AP Chem - we derived the Henderson-Hasselbalch equation and showed the STRICT condition under which we could simply enter the INITIAL concentrations of the conjugates (from the question data/info) and know that these concentrations would PRACTICALLY be the same as their EQUILIBRIUM concentrations, the concentrations that MUST be used in any K expression.
We then showed that, when used appropriately i.e. when you can "neglect x/ % ionization", the formula yield a very quick and easy answer for the pH of the buffer.
We then did a more complex problem in which two solutions are mixed to form a buffer, so an initial molarity calculation must first be done.
We then discussed the meaning of "in phase" and "out of phase" with respect to:
1. two points on a given wave
2. two separate waves.
Two waves that are in phase will have constructive interference throughout.
We then introduced the term "resonance", which occurs when a wave (of energy) produces and in-phase wave in an object that will vibrate at the SAME frequency of the incoming wave, thus producing the maximum constructive interference, i.e. resonance!
We finished up the problems in Waves 4, and then we did a lab in which we measured the speed of sound in air at room temperature.
AP Chem - we derived the Henderson-Hasselbalch equation and showed the STRICT condition under which we could simply enter the INITIAL concentrations of the conjugates (from the question data/info) and know that these concentrations would PRACTICALLY be the same as their EQUILIBRIUM concentrations, the concentrations that MUST be used in any K expression.
We then showed that, when used appropriately i.e. when you can "neglect x/ % ionization", the formula yield a very quick and easy answer for the pH of the buffer.
We then did a more complex problem in which two solutions are mixed to form a buffer, so an initial molarity calculation must first be done.
# posted by C @ 8:37 AM 
