Post-Assessment #34  [ENDORSED]


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Alysia Garcia 1B
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Joined: Wed Feb 21, 2018 3:02 am

Post-Assessment #34

Postby Alysia Garcia 1B » Sat Apr 21, 2018 4:37 pm

In this problem:
If an electron (mass 9.11 x 10-31 kg) has an associated wavelength of 7.28 x 10-9 m, what is its speed? Is your answer reasonable, why?
I got the answer 1x10^-5 m/s, but how would you determine if the speed is reasonable?

KateCaldwell 1A
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Joined: Fri Apr 06, 2018 11:02 am

Re: Post-Assessment #34  [ENDORSED]

Postby KateCaldwell 1A » Sat Apr 21, 2018 7:28 pm

I believe a speed is reasonable if it is less than the speed of light (3.00x10^8 m.s^-1). Your answer seems to be correct then because it is much smaller than the speed of light.

Natalie Noble 1G
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Re: Post-Assessment #34

Postby Natalie Noble 1G » Sat Apr 21, 2018 7:35 pm

This is awkward but you may want to recheck your calculations. The answer shouldn't be negative, it should be 1.00 x 10^5 m/s (if it were negative that would be an extremely slow electron). The reason 1.00 x 10^5 m/s makes sense is because the electron is moving slower that the speed of light, which makes sense (it is not possible to move faster than the speed of light).

Maya Khoury
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Re: Post-Assessment #34

Postby Maya Khoury » Sun Apr 22, 2018 3:00 pm

I attached a picture below of me trying to find the speed for this problem but for some reason i always end up with a ridiculously large number. Can someone tell me what I'm doing wrong? I'm sure it's a stupid mistake lol

thank you !
Attachments
IMG_0828.JPG

Chem_Mod
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Re: Post-Assessment #34

Postby Chem_Mod » Sun Apr 22, 2018 3:30 pm

Your denominator value should be more closer to 10-40 order of magnitude not 10-49

Mario Reyes 1C
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Re: Post-Assessment #34

Postby Mario Reyes 1C » Sun Apr 22, 2018 10:58 pm

Maya Khoury wrote:I attached a picture below of me trying to find the speed for this problem but for some reason i always end up with a ridiculously large number. Can someone tell me what I'm doing wrong? I'm sure it's a stupid mistake lol

thank you !


The denominator should be 10^-39, not 10^-49


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