Chapter 27 Homework
1. (p.854 prob.2) What is the velocity of a beam of electrons that go undeflectd when passing through crossed electric and magnetic fields of magnitude 1.38 x 104V/m and 2.90 x 10-3T, respectively? What is the radius of the electron orbit if the electric field is turned off?
2. (p.854 prob.9) A child's swing has a natural frequency of 0.90Hz. (a) What is the separation between possible energy values (in joules)? (b) If the swing reaches a vertical height of 45cm above its lowest point and has a mass of 20kg (including the child), what is the fractional change in energy between levels whose quantum numbers are n? (c) What is the fractional change in energy between levels whose quantum numbers are n (as just calculated) and n + 1? Would quantization be measurable in this case?
3. (p.855 prob.18) Barium has a work function of 2.48eV. what is the maximum kinetic energy of electrons if the metal is illuminated by light of wavelength 390nm? What is their speed?
4. (p.855 prob.30) A gamma-ray photon produces an electro-positron pair, each with a kinetic energy of 345keV. What was the energy and wavelength of the photon?
5. (p.856 prob.42) Calculate the ratio of the KE of an electron to that oaf a proton if their wavelengths are equal. Assume that the speeds are no-relativistic.