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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: echonet on October 25, 2007, 10:01:55 PM

Title: Checking my answers against the book's...
Post by: echonet on October 25, 2007, 10:01:55 PM

I am doing some calculations of velocity based on wavelength and mass (using the formula v=h/(wm)) and I'm getting a different scientific notation exponent for each and every answer. Here are 2 examples (wavelength = 750 nm for both, or 7.50e-7)

Mass =  9.10939e-28 grams
     I get: 9.70e-1
     Book gets: 9.70e2

Mass = 1.67262e-24 grams
     I get: 5.29e-4
     Book gets: 5.29e-2


What am I doing wrong (this is somewhat urgent)?

Any help is VERY GREATLY appreciated!

Title: Re: Checking my answers against the book's...
Post by: enahs on October 25, 2007, 10:53:49 PM

What is the units in Planck's Constant? Are your units canceling?