## Video module Test

derinceltik1K
Posts: 51
Joined: Sat Aug 17, 2019 12:15 am

### Video module Test

If 3.607 x 10-19 J is required to remove an electron with zero kinetic energy from a metal surface, what would be the longest wavelength light that could do this?

How would we be able to use the J with the equations?

Posts: 104
Joined: Fri Aug 09, 2019 12:16 am

### Re: Video module Test

If there is no kinetic energy, then the energy required to remove an electron from the metal is equal to the energy of the photon beam being directed at the metal. from there you use the equation E=hv to find the frequency, then c= (wavelength)(frequency) to find the greatest wavelength of light that can remove electrons from the metal.

Callum Guo 1H
Posts: 134
Joined: Fri Aug 02, 2019 12:15 am
Been upvoted: 1 time

### Re: Video module Test

to find the longest wavelength first you would have to find the frequency of the wave. You get that through E=hv. where v= E/h. Then you would plug v into the equation c=(wavelength)(v) and then solve for wavelength.

Ashley Fang 2G
Posts: 102
Joined: Fri Aug 30, 2019 12:17 am

### Re: Video module Test

Or, you could use the combined equations of E=hv and c=v(wavelength) to get (wavelength)=hc/E and solve for wavelength!
Hope that helps :)