## Unit Conversions

$c=\lambda v$

Yazmin Bocanegra 3L
Posts: 51
Joined: Thu Jul 25, 2019 12:17 am

### Unit Conversions

What's the easiest way to convert from nanometers to picometers, etc? My skills are a little rusty.

AnnikaMittelhauser4E
Posts: 50
Joined: Fri Aug 30, 2019 12:18 am

### Re: Unit Conversions

I'm sure it's different for everyone, but personally I find it easiest to just convert to meters in the middle since we know the conversion factors relating to meters. Ex: Convert 400 nm to pm.

(400 nm) x (1 m/10^9 nm) x (10^12 pm/1 m) = 400,000 pm

You can tell that all the units except pm cancel.

Alternatively, we know that nm is 10^-9 m and pm is 10^-12 m so nm are 10^3 larger. So you can multiply 10^3 x 400 pm and get 400,000 pm too.

Micah3J
Posts: 100
Joined: Tue Oct 08, 2019 12:16 am

### Re: Unit Conversions

Can someone confirm that a keV is really 10^3 eV which is equal to 1.602x10^-19 J?

005206171
Posts: 107
Joined: Wed Sep 18, 2019 12:20 am

### Re: Unit Conversions

This is my method: I put the units that i have on the bottom, and the units i want on top. I put a 1 next to the bigger units. Then for the smaller units, I subtract the scientific notations of the bigger unit from the smaller unit. Then I multiply these factors.

Ex: 18.2 nm in cm?
18.2 x 1 cm/10^7 nm
where (-2) - (-9) = 7 because cm=10^-2 and nm=10^-9

for lengths: square top and bottom of your ratio
for volume: cube top and bottom of your ratio

Jenna Ortiguerra 4G
Posts: 50
Joined: Sat Aug 17, 2019 12:18 am

### Re: Unit Conversions

I typically make a conversion table, similar to the one I would use for a stoichiometry problem to make unit conversions.
1nm = 1x10^-9m, 1m= 1x10^12

1nm x ((1x10^-9m)/(1000nm)) x ((1m)/(1m)) = 1000 pm
Thus, 1nm=1000pm

Alternatively, when converting from nm to pm, you can move the decimal of the number three times to the right. When converting from pm to nm, you can move the decimal three times to the left.

RobertXu_2J
Posts: 104
Joined: Fri Aug 30, 2019 12:17 am

### Re: Unit Conversions

The way I do it is I convert it to meters first before finishing the calculations. Using your example, lets assume that we have 100 nm. Then 100 nm x (1 m/10^9 nm) x (10^12 pm/1 m) = 100,000 pm. Although this may take longer than converting directly, it makes sure that your answer is correct.

stephaniekim2K
Posts: 79
Joined: Fri Aug 09, 2019 12:16 am

### Re: Unit Conversions

I find it easier to convert when you first convert to meters, then to the needed measurement from there.