## hw problem 1B.23

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

Joanna Mendoza 3J
Posts: 20
Joined: Sat Aug 24, 2019 12:17 am

### hw problem 1B.23

problem: What is the velocity of a neutron of wavelength 100. pm?

when we are given the wavelength in pm or any other unit, do we need to change it to nm before we plug it into our equation?

Vicki Liu 2L
Posts: 101
Joined: Sat Aug 24, 2019 12:15 am

### Re: hw problem 1B.23

It depends on the equation you're using because you want to make sure the unit for wavelength matches the units of other constants/values so that all the units cancel out nicely. In this case and most cases in general, wavelength should be changed to meters before being used in calculations.

Alexa Mugol 3I
Posts: 54
Joined: Sat Aug 17, 2019 12:17 am

### Re: hw problem 1B.23

Actually, I believe most equations use meters for wavelength. So you would convert the given wavelength, whether in nm or pm, to m when doing calculations.

Jasmine Vallarta 2L
Posts: 102
Joined: Sat Aug 17, 2019 12:18 am

### Re: hw problem 1B.23

it would be easier to convert to meters first as the equations use m and not pm or nm

Kristina Rizo 2K
Posts: 105
Joined: Wed Sep 18, 2019 12:19 am

### Re: hw problem 1B.23

Adding on to this question, does anyone know if we will be given a chart of mass values for future tests? Because in the question, we were only given the wavelength and not the mass of a neutron.