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### Work Function

Posted: **Sat Oct 13, 2018 6:42 pm**

by **chrisavalos-2L**

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?

### Re: Work Function

Posted: **Sat Oct 13, 2018 6:44 pm**

by **Elena Saab 4A**

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

### Re: Work Function

Posted: **Sat Oct 13, 2018 8:42 pm**

by **Tarika Gujral 1K**

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).

### Re: Work Function

Posted: **Sat Oct 13, 2018 9:25 pm**

by **Tarika Gujral 1K**

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).

### Re: Work Function

Posted: **Sun Oct 14, 2018 2:48 pm**

by **Hannah Yates 1K**

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).