## formula for light problems

$c=\lambda v$

Alondra Juarez section 1E
Posts: 47
Joined: Fri Sep 29, 2017 7:03 am

### formula for light problems

I noticed that Dr. Lavelle rearranged the formula of E=hv and c= λv in Fridays lecture to solve the problem given in class and he got E=hc/λ, do we always have to do this in order to solve the problem? how do we know we have to rearrange the equations?

Jasmine Emtage-1J
Posts: 24
Joined: Fri Apr 06, 2018 11:02 am

### Re: formula for light problems

I'm not sure that we'll always have to rearrange these equations, but for this problem we did because we were not given frequency (v). In order to find frequency we had to solve E=hv for v (v=E/h). The problem was asking for wavelength so we solved c=('lambda')(v) for lambda (lambda=c/v) and substituted v for E/h.

Elena 1H
Posts: 27
Joined: Fri Apr 06, 2018 11:04 am
Been upvoted: 1 time

### Re: formula for light problems

It depends on the values you have and what you are solving for. Its not always necessary to rearrange equations it just depends on what you're given to begin with.