Achieve #14
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Achieve #14
Hi, I'm having trouble with this problem. The process seems straightforward, use Debroglie's equation, rearranging it solve for velocity, v=h/m*λ, and plugging in the wavelength they gave in meters, which would be 6.25*10^-7 m and the mass of each particle in kg, and solving for v. But I keep getting it wrong for some reason, despite double checking my work. I also use 4 sig figs. Can someone help?
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- Posts: 126
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Re: Achieve #14
Hi,
I think your issue might come from not putting parentheses around m*λ in your calculator because everything else seems like it has been set up properly. Your equation should look like v=h/(m*λ) and not just v=h/m*λ.
I think your issue might come from not putting parentheses around m*λ in your calculator because everything else seems like it has been set up properly. Your equation should look like v=h/(m*λ) and not just v=h/m*λ.
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Re: Achieve #14
It seems like you have everything set up correctly, so you should be getting the correct answers. The only issues I can think of are related to inputting the numbers in the calculator. I would recommend to put parenthesis around each value such that (6.63*10^-34)/((m)*(λ)) or (6.63*10^-34)/(m)/(λ). The process could be a little tedious but it ensures accuracy in calculation. Also try not to use the 2nd->ANS function on the calculator since (I could be wrong) it uses the previous answer which might not be the value you need. I hope this was helpful!
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Re: Achieve #14
Hi!
I kept getting these problems wrong too. I was using the same equation as you and plugging it into my calculator with the right parenthesis. I then realized that the mass was in KILOGRAMS haha. So I say just make sure your units are the correct ones.
Hope this helps!
I kept getting these problems wrong too. I was using the same equation as you and plugging it into my calculator with the right parenthesis. I then realized that the mass was in KILOGRAMS haha. So I say just make sure your units are the correct ones.
Hope this helps!
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- Posts: 105
- Joined: Fri Sep 24, 2021 5:32 am
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- Posts: 105
- Joined: Fri Sep 24, 2021 5:32 am
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Re: Achieve #14
Try using more parentheses! I use excessive parentheses, especially since we are using a lot of scientific notation. I was having this problem as well.
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Re: Achieve #14
Yes...just convert to g to kg, so it can cancel out with the joules from Plank's constant and make sure to convert the wavelength from nm to m.
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Re: Achieve #14
I would write out all of the units to make sure and also use parenthesis for everything.
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- Posts: 101
- Joined: Fri Sep 24, 2021 6:10 am
Re: Achieve #14
Since it looks like all your units are correct and you're using the correct equation I would reccoment writing out exactly what you need to plug in the calculator (with parenthesis, around every unit to really separate each number) so that way you can really make sure you are plugging it correctly into your calculator. Also, I don't know if you're doing this but I would convert from g to kg before plugging in the entire equation.
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