2/25/09

Newton's Law of Cooling and Waves

Physics reviewed for tomorrow's test and worked on an activity for calculation heat transfer associated with temperature change and with phase change. The solutions for this are posted on the class website.

Physical Science reviewed their film question and the issue of simple harmonic motion and discussed transverse and longitudinal waves. Tomorrow, we will review transverse/longitudinal waves and add surface waves to our wave-classification scheme. I have a few video clips to illustrate the different wave types and we should have time to begin discussing wave features and wave speed.

Honors Physics performed a lab demonstrating Newton's Law of Cooling. C block had some calculation issues and it took me a bit to figure out why. (1) T0 means original temperature difference (water temp - room temp), NOT original temperature of water. Not many people seemed to notice that distinction. (2) The k value was based on time in minutes (your x-axis reported time in minutes). For the prediction of temperature at 800 seconds, you had to use 13.3 minutes for the t value in the calculation. Your overall technique was just fine, just a few little issues kept the value from being close to the actual, measured value.

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