Questions from Modern Physics

Q: Most black-and-white photographic film (with the exception

Most black-and-white photographic film (with the exception of some special-purpose films) is less sensitive to red light than blue light and has almost no sensitivity to infrared. How can these proper...

Q: A photon has momentum of magnitude 8.24 * 10-

A photon has momentum of magnitude 8.24 * 10-28 kg.m/s. a. What is the energy of this photon? Give your answer in joules and in electron volts. b. What is the wavelength of this photon? In what regi...

Q: How could you very quickly make an approximate measurement of the focal

How could you very quickly make an approximate measurement of the focal length of a converging lens? Could the same method be applied if you wished to use a diverging lens? Explain.

Q: The photoelectric threshold wavelength of a tungsten surface is 272 nm.

The photoelectric threshold wavelength of a tungsten surface is 272 nm. Calculate the maximum kinetic energy of the electrons ejected from this tungsten surface by ultraviolet radiation of frequency 1...

Q: When ultraviolet light with a wavelength of 254 nm falls on a

When ultraviolet light with a wavelength of 254 nm falls on a clean copper surface, the stopping potential necessary to stop emission of photoelectrons is 0.181 V. a. What is the photoelectric thresh...

Q: X rays with initial wavelength 0.0665 nm undergo Compton scattering

X rays with initial wavelength 0.0665 nm undergo Compton scattering. What is the longest wavelength found in the scattered x rays? At which scattering angle is this wavelength observed?

Q: An electron and a positron are moving toward each other and each

An electron and a positron are moving toward each other and each has speed 0.500c in the lab frame. a. What is the kinetic energy of each particle? b. The e+ and e- meet head-on and annihilate. What...

Q: A 75-W light source consumes 75 W of electrical power

A 75-W light source consumes 75 W of electrical power. Assume all this energy goes into emitted light of wavelength 600 nm. a. Calculate the frequency of the emitted light. b. How many photons per s...

Q: A laser used to weld detached retinas emits light with a wavelength

A laser used to weld detached retinas emits light with a wavelength of 652 nm in pulses that are 20.0 ms in duration. The average power during each pulse is 0.600 W. a. How much energy is in each pul...

Q: The high-energy photons can undergo Compton scattering off electrons in

The high-energy photons can undergo Compton scattering off electrons in the tumor. The energy imparted by a photon is a maximum when the photon scatters straight back from the electron. In this proces...