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You will record a few numbers and perform some algebra. Plug in your numbers and do the proper unit conversions.

We hope you had a good break from school!

Enjoy this first lab. Please be careful with the quiz deadlines!


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Laser Diffraction


With regards to question 7, I'm not quite sure how to write the significant figure into the box to make it correct for the automatic correcting system. I've tried both (different numbers are being used) 4.255E-04 and 0.0004255. What am I doing incorrectly? Thank you.
Mon. 22, Jan 2007, 12:27
Oops, My bad!!!! I had 10E-6 instead of 1E-6 in my conversion calculation. Good catch. It is fixed now and will retro-actively correctly assess any student who had the correct answer previous to this time stamp. Thanks again, Douglas. P.S. The other reason your answer showed up as incorrect is because you transposed two numbers.Douglas
Mon. 22, Jan 2007, 16:02

Umm... I took Physics 1 more than a year ago, so my memory is a little rusty... For question 1 of the postlab, how exactly do I "justify the uncertainty."Anonymous
Wed. 24, Jan 2007, 20:45
Good question.
Sometimes you will say (Uncertainty found from resolution of meter stick.)
Other times you will say (Uncertainty found from standard deviation of repeated measurements.)
For the distance called x in this lab, you might say
± 3[mm] (Uncertainty is due to parallax.)
Fri. 26, Jan 2007, 05:18

Hi Douglas, I am having trouble with prelab questions 1 and 6. For problem 1. my question asks what is the ratio of nanometer and meter. To find the answer I took 1E-9/1E0=1E-9 is this the correct way to calculate this or is it 10E-9/10E0? I am not able to get the right answer. Secondly for nanometer and millimeter I did 10E-9/10E-3=.000001 and also put in my calculator 10E3/10E9=.000001 and I got it wrong. I feel really silly that this is so difficult, but please help.
Sat. 10, Nov 2007, 23:00
There are 109 nanometers per meter.

109 [nm] : 1 [m] = 109 [nm/m]


1 : 10-9 = 109 [nm/m]

Question 6:
There are 106 nanometer in one millimeter.

106 [nm] : 1 [mm] = 106 [nm/mm]
Mon. 12, Nov 2007, 08:42

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