The peak intensity of the CMBR occurs at a wavelength of 1.1 mm. (a) What is the energy in eV of a 1.1-mm photon? (b) There are approximately 109 photons for each massive particle in deep space. Calculate the energy of 109 such photons. (c) If the average massive particle in space has a mass half that of a proton, what energy would be created byconverting its mass to energy? (d) Does this imply that space is “matter dominated”? Explain briefly.

When you shine a certain source of EM radiation on a sheet of gold (work function W1 = 5.1 eV), the stopping voltage required to bring all the ejected electrons to a halt is V = 3.5 V. If you were to use this same source of EM radiation on a sheet of potassium (work function W2 = 2.3 eV), what would be the maximum speed of ejected electrons?

I'm still confused about the step 2 part. How would I put this into my calculator? Where do the extra numbers 232.6 come from?

I need help trying to figgure out how to fill out the graph by just using the info on the graph

An electron and an antielectron (each has mass 9.11 x 10-31 kg), each traveling at 0.6c relative to the lab frame, collide head on and annihilate, resulting in the creation of two identical photons which travel away in opposite directions. What is the frequency of each photon?

An ultra high energy electron (ß ≈ 1) emits a photon. (a) Derive an expression to express the emission angle 0 in the lab system in terms of 0*, the angle of emission in the rest frame of the electron. Also, (b) Show that half of the photons are emitted within a cone of half angle 01/y.

An antiproton has the same mass and rest energy (938.3 MeV) as a proton, but has a negative change -e instead of the positive charge +e of the proton. A proton and an antiproton, initially far apart, move toward each other with the same speed and collide head-on, annihilating each other and producing two photons. Find the energies and wavelengths of the photons if the initial kinetic energies of the proton and antiproton are (a) both negligible and (b) both 545 MeV.

Astronaut A performs an experiment on a spaceship where he measures the speed of photons (light particles) using a laser. He measures the speed of the photons to bec with respect to his spaceship. Another spaceship moves past astronaut A's ship with speed V = 0.8c in the same direction as the photons %3D in astronaut A's experiment is moving. What speed does astronaut B measure for the photons of astronaut A's experiment?

Calculate the following: Calculate the wavelength that an astronaut radio must be tuned to to sense signals from electrons from level n=273 to level n=272. Find the speed of the electron?