DeBroglie Units

$\lambda=\frac{h}{p}$

NatBrown1I
Posts: 62
Joined: Fri Sep 28, 2018 12:17 am

DeBroglie Units

Why does the De Broglie equation use kg instead of grams?

405021651
Posts: 46
Joined: Tue Nov 14, 2017 3:03 am

Re: DeBroglie Units

kg is in SI units , grams is not

904914037
Posts: 65
Joined: Wed Sep 18, 2019 12:16 am

Re: DeBroglie Units

Yes, the DeBroglie equations uses SI units for all of the units involved in the equation. It is important to also remember that velocity is meters per seconds. So if you are given anything other than these units, for example kilometers per hour, you would have to convert this to meters per second.

Joanne Lee 1J
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

Re: DeBroglie Units

You also need to remember that you are dividing Planck's constant by the momentum and the units for Plank's constant is J(s) where Joules is kg⋅m2⋅s−2. So, in order for the two masses units to cancel out, you have to use kg in the denominator as well. It's always about using the same units as the constants given so the units can cancel out.