WMS Science Teachers

Because of this, and despite the fact that it is common practice, it is sort of a mistake to find the resistance of a circuit element by plotting V vs I and finding the slope. Obviously, if the circuit element is non-ohmic it doesn’t make any sense to report a single R value. However, even if the circuit element can be nicely approximated by Ohm’s Law, it actually makes more sense to report the value of R as an average of all V/I ratios than it does to calculate the resistance by determining the slope of the best fit line.  This is especially the case if your best fit-line has a non-zero y-intercept.

BTW: Mazur also noted in our conversation that his years of experience on the Physics AP design committee made him less than enthusiastic about AP’s. He has data showing that student who got 5s on the Physics AP do worse than other Harvard Physics students who did not take the AP’s – a sobering thought.

Just as you make sure your socks are on before your shoes, cells make sure that their chromosomes are properly aligned before they divide. However, every time a cell divides, it runs the risk of generating cells with too few or too many chromosomes. These mistakes can cause Down Syndrome and play a role in the growth of cancers. In his Science Center Lecture Series presentation, professor Andrew Murray looks at a mysterious cellular process that may provide clues to understanding chromosomal abnormalities such as the higher incidence of children with Down Syndrome born to older women.