Saturday, May 16, 2009

Coulomb's Law

Coulomb's log: After several weeks of piddling, I've done enough exercises to move on from this section of a chapter of a college physics textbook (1996) on Coulomb's Law. The main take away is Coulomb's Law:

F=k*q1*q2/r squared

The net force from two electric charges equals a constant (9*10 to the 9th) times the absolute value of q1 times q2 (two charges) divided by the distance between the two charge squared.

Following the process of how Coulomb developed this formula, I've understood more clearly than ever how scientists developed these sorts of formulas. They first figured out proportionalities. Is the force proportionate to the charge? To the product of the charges? Is it proportionate to the distance? Inversely proportionate?

Having then arrived at a set of proportions, namely that the force of two charges is directly proportionate to the product of the two charges and inversely proportionate to the square of the distance between the two charges, they then slap a constant to make the proportions into an equality. Then experimentally they figure out what the constant is.

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