## Momentum [ENDORSED]

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

304744081
Posts: 6
Joined: Thu Feb 02, 2017 3:00 am

### Momentum

If you are given the velocity and you are asked to find the kinetic energy, is there a constant that is used for the mass in kilograms? Does it change depending whether its a photon, electron, etc...?

Carlos Gonzales 1H
Posts: 50
Joined: Fri Sep 29, 2017 7:05 am
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### Re: Momentum  [ENDORSED]

I believe you would be given the mass also, typically the mass of a subatomic particle is given as kilograms in the DeBroglie equation

mendozayael_2H
Posts: 31
Joined: Fri Sep 29, 2017 7:06 am

### Re: Momentum

The mass variable (m) will change according to what particle/object is given. I'd say typically the particle will be an electron, who's mass is 9.1093 x 10^(-31) kg, so you can use that. But the question should let you know what particle is being observed, and you would use that particle's mass for the m variable.

Beza Ayalew 1I
Posts: 58
Joined: Fri Sep 29, 2017 7:07 am

### Re: Momentum

Yea, it would be good to know the mass of an electron just as common chem knowledge, but I'm pretty sure he gave the mass of a proton, neutron and an electron on the last exam so you should generally be able to find the mass on the actual exam.