# Algebra

Mrs. Babich

Algebra Period 4

April 1, 2014

Extra Credit Project

12. When you flip a light switch, the light seems to come on almost immediately, giving the impression that the electrons in the wiring move very rapidly. Part A: In reality, the individual electrons in a wire move very slowly through wires. A typical speed for an electron in a battery circuit is 5.0x10 to the -4th meters per second. How long does it take an electron moving at that speed to travel a wire 1.0 centimeter, or 1.0x10 to the -2nd? Part B: Electrons move quickly through wires, but electric energy does. It moves at almost the speed of light, 3.0x10 to the 8th meters per second. How long would it take to travel 1.0 centimeters at the speed of light? Part C: Electrons in an ordinary flashlight can travel a total distance of only several centimeters .suppose the distance an electron can travel in a flashlight circuit is 15 centimeters, or 1.5x10 to the -1st meter. The circumference of the earth is about 4.0x10 to the 7th meters. How many trips around the earth could a pulse of electric energy make at the speed of light in the same time an electron could travel through 15 centimeters of a battery circuit in 5.0x10 to the -4th meters per second?

For part A, the first step is to put (5.0) to the 10th to the -4th. The numerator would be (0.00050) if someone were trying to put 5.0x10 to the -4th in the form it’s supposed to be in. For the second scientific problem, (1.0x10 to the -2nd power), it would come out to be 0.01 on the bottom. When dividing 0.00050 into 0.01, the answer would come out to be 0.05. You wouldn't write your answer in standard form, you would write your answer in scientific notation. It would take an electron 0.05 seconds, or 5x10 to the 2nd power, to travel through a 1.0 centimeter wire.

The next part has to deal with electric energy and how long it would take through a 1.0 centimeter wire at the speed of light. Electric energy travels at the...

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