The photoelectric equation for the kinetic energy of a photoelectron is, following Einstein, E ≤ hf − W, where h is Planck’s constant, f is the frequency of the light, and W is the work-function. Sodium has W = 3.2×10−19 J. When sodium is illuminated by monochromatic light of a particular frequency, electrons are emitted with speeds up to 8 × 105 m s−1 . a) Calculate the wavelength of the light. b) Calculate the stopping potential.

Ex. 51: Calculate the energy of a photon in light of wavelength 5000 A.

When light with a wavelength of 208 nm is incident on a certain metal surface, electrons are ejected with a maximum kinetic energy of 3.59 × 10-19 J. Determine the wavelength (in nm) of light that should be used to double the maximum kinetic energy of the electrons ejected from this surface.

An electron of mass 9.11 × 10−31 kg and a bowling ball of mass 6.00 kg each have 4.50 eV of kinetic energy.  Calculate the de Broglie wavelength of the electron: Calculate the wavelength of a 4.50 eV photon:

Data for the photoelectric effect of silver are given in the table. Frequency of incident radiation (1015 ?−1)(1015⁢ s−1) Kinetic energy of ejected electrons (10−19 ?)(10−19 J) 2.00 5.90 2.50 9.21 3.00 12.52 3.50 15.84 4.00 19.15 Using these data, find the experimentally determined value of Planck's constant, ℎh , and the threshold frequency, ?0ν0 , for silver.

A monochromatic light source illuminates the surface of metal X. The maximum kinetic energy of electrons leaving the surface of the metal is shown in the graph above.An ammeter is connected to the standard photoelectric effect circuit to measure the photoelectric current arising from the electrons moving between the cathode and anode of the vacuum tube containing the illuminated sample. The current is found to be 12.4mA when the metal is illuminated with a wavelength of 184.2nm.What is the energy (eV) of the photons striking metal X?

In 1893, physicist Wilhelm Wien showed that the wavelength of maximum thermal emission strength of electromagnetic radiation from a blackbody at temperature T obeys: Amax T 2.898 mm.K. = This result, known today as Wien's Law, is very useful for, among other things, esti- mating the temperature of distant objects based on the color of light they emit. (a) Planck's spectral energy density function is usually written as an energy per range df of frequencies. Quite often, however, it is more convenient to express it as an

Calculate the maximum wavelength, Amax, of electromagnetic radiation that could eject electrons from the surface of copper, which has a work function of 7.26 x 10-1⁹ J. Amax = λ = m If the maximum speed of the emitted photoelectrons is 4.92 x 106 m/s, what wavelength of electromagnetic radiation struck the surface and caused the ejection of the photoelectrons? m

If the photoelectric work function of a metal is 5 eV, calculate the threshold frequency for the metal. Given : Planck's constant 6.6 x 10-* Js. 1 eV = 1.6 x 10- 19 V.

No photoelectrons are emitted from tungsten unless the wavelength of incoming light is less than 270 nm. If an experiment requires electrons with a maximum kinetic energy of 2.0 eV, what frequency of light should be used to illuminate the tungsten?