When light with wavelength 640 nm shines on a particular sheet of metal, it ejects electrons that have a maximum kinetic energy of 0.3 ev . what is the maximum kinetic energy of ejected electrons if we shine light with wavelength 300 nm on the sheet of metal instead?

To solve this problem it is necessary to apply the concepts related to energy in photons. Although these although they have no mass have energy and are defined as

Where,

c = Speed of light

h = Planck's constant

= wavelength

f= Frequency of the radiation

In addition to this we know that the maximum kinetic energy in a photon is given by the formula

Where,

Amount of energy binding the electron to the metal

can be expressed also as

Replacing the terms then we have to

Re-arrange to find

Replacing with our values,

Therefore the maximum kinetic energy is 2.49eV

Note: Speed of light is converted to nanometers.

in physics zero. in muscle fatigue could be high

the temperature in kelvin of 2.0 dm3 of an ideal gas is doubled and its pressure is increased by a factor of four. what is the final volume of the gas