Kinetic Energy

[kevinav]

Can kinetic energy, obtained from the equation Ek=mv^2, be used in the equation E=h(frequency)? Is kinetic energy the same as the energy used in this equation?

[Ronak Singh]

Yes, the energy in both equations should be equivalent.

[kevinav]

Correction: Ek= (1/2)mv^2

[Yousif Jafar 1G]

No, the kinetic energy that you derive from Ek=1/2mv^2 can be related to frequency by using the formula Ek=hv-ϕ. So practically what this equation does is it sets the kinetic energy of the ejected electron equal to the energy supplied by the photon minus the work function (threshold value) that is needed to eject the electron. The E=hv is the measure of the energy in one photon. The Ek is the energy of the electron.