question help?

[TMJ]

Calculate the kinetic energy of one electron, if it has a work function of 1.9eV and a frequency of 7.3 x 10^14

Help Please

[sunny246]

can i ask you a question?
Im new to this and i was wondering how you ask questions on this thing as you have done.
thanks

[Lasercookie]

can i ask you a question?
Im new to this and i was wondering how you ask questions on this thing as you have done.
thanks

Go the the index of the board you want, e.g. 'physics' (the page where it lists all the threads). If you look to the right, you'll see a button that says 'New Topic' click that to create a new thread.

[Ancora_Imparo]

You would use the equation: E_{K_Max} = h*f - W

Since the work function (W) is given in eV, you would use the eV value for Planck's constant (h) which is 4.14*10^-15 eV s.

Thus: E_{K_Max} = (4.14*10^-15) * (7.3*10^14) - 1.9 = 1.12 eV
If you wanted to convert it to Joules, you would divide multiply this value by the charge of an electron, which is 1.6*10^-19 C.

Note: All the values I've stated above are given in the data book, but memorising them helps! You'll end up doing so many questions that you'll probably memorise it anyway!

[TMJ]

don't you times by 1.6 x 10^-19 to convert to joules

[Phy124]

don't you times by 1.6 x 10^-19 to convert to joules

1 eV is approximately equal to 1.6 x 10^-19 Joules, so yes, you would multiply it by this value rather than divide.

[Ancora_Imparo]

Sorry, my bad... multiply it is.

[TMJ]

No worries

And 1 more question does reflected light support both the wave and particle model of light?

[Ancora_Imparo]

Yes, reflection of light supports both models, as does refraction for that matter.