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View Full Version : Scientific Notation's Got Me Blown!


Edin_Dzeko
Jul26-11, 12:55 AM
1. The problem statement, all variables and given/known data
A laser used to dazzle the audience in a rock concert emits green light with a wave length of 515 nm. Calculate the frequency of the light.


2. Relevant equations

V = C/Lambdah

3. The attempt at a solution
http://img36.imageshack.us/img36/7982/unledpg.jpg (http://imageshack.us/photo/my-images/36/unledpg.jpg/)

** In the image I forgot to knock off the "nm" after I did the dimensional analysis to convert it to m disregard it***

My answer when I put it in my calculator is what's in the image but the book has the correct answer as: 5.83 x 10^14 s

How did they get 10x^14? If the bases aren't the same what happens to the exponents?

There was another problem which was solved by the book itself:

3.00 x 10^8 m/(s/s) - **(means s cancels out)
---------------------------
4.62 x 10^14 /(s/s) - ** (means s cancels out)

= 6.49 x 10^-7 m (how did they get -7?)!


Btw, I'm doing the wavelength and frequency equation in Chemistry.

Pengwuino
Jul26-11, 02:06 AM
When you put it into your calculator, you did {{3x10^8}\over{515}}*10^-9 to get that answer. Make sure you enclose the 10^-9 part in the denominator with parenthesis.

zaldar
Jul30-11, 09:17 PM
correct and I love your tagline pengwuino amazingly some physicists I know that don't believe in evolution....truly I fear for my country and the world...

Pengwuino
Jul30-11, 09:22 PM
correct and I love your tagline pengwuino amazingly some physicists I know that don't believe in evolution....truly I fear for my country and the world...

Thanks. Someone else on the forum actually said it and I stole it from him to use as a signature.

Unfortunately, a couple people have said "Oh so you think evolution is fake huh!".

zaldar
Jul30-11, 09:33 PM
good lord.....people here? Do they not understand science...???? Theory in science means FACT. RAGE!!!!! Sigh....I mean theory of gravity anyone?

Pengwuino
Jul30-11, 09:38 PM
good lord.....people here? Do they not understand science...???? Theory in science means FACT. RAGE!!!!! Sigh....I mean theory of gravity anyone?

Hmm careful, no it doesn't. In scientific context, "facts" are few and far between. A theory in science really has its own meaning that is not exactly like "fact" and far from the lay term "theory".