## Work Function

chrisavalos-2L
Posts: 63
Joined: Fri Sep 28, 2018 12:18 am

### Work Function

I was wondering if we are given an instance where we have the mass of an electron but not the velocity and are asked to find the threshold energy, is there a way to calculate the velocity in this instance or would they have to give us the velocity in this situation?

Elena Saab 4A
Posts: 43
Joined: Fri Sep 28, 2018 12:27 am

### Re: Work Function

I believe you would need to know either the threshold frequency or the velocity to answer this type of problem.

Tarika Gujral 1K
Posts: 62
Joined: Fri Sep 28, 2018 12:27 am

### Re: Work Function

More information would need to be provided, unless the problem specifies kinetic energy is 0 (i.e. longest wavelength). In this case, set threshold energy equal to energy of photon (velocity does not need to be calculated).

Tarika Gujral 1K
Posts: 62
Joined: Fri Sep 28, 2018 12:27 am

### Re: Work Function

More information would need to be provided, unless the problem specifies kinetic energy is 0 (i.e. longest wavelength). In this case, set threshold energy equal to energy of photon (velocity does not need to be calculated).

Hannah Yates 1K
Posts: 59
Joined: Fri Sep 28, 2018 12:27 am

### Re: Work Function

In order to find the velocity, you would need the Energy of the ejected election. That means that you would either need the given the energy of the ejected electron or have a way to calculate it with the given information using the equation E(photon) - Threshold energy = E(electron).