If the energy of a photon is measured in eV and its momentum is measured in eV/c, how do the two compare?
  1. The momentum is bigger.
  2. They are the same.
  3. The energy is bigger.
  4. If it is infrared light or longer, the momentum is bigger. Otherwise the energy is bigger.
  5. If it has a shorter wavelength than x-rays, the energy is bigger. Otherwise the momentum is bigger.



For slow speeds, how does the relativistic momentum measured in eV/c compare with the relativistic energy E measured in eV?
  1. The momentum is always a lot bigger than the energy.
  2. The energy is always a lot bigger than the momentum.
  3. The momentum and energy are approximately equal.
  4. The momentum goes to zero as the speed approaches zero.
  5. The energy approaches zero as the speed approaches zero.



If the relativistic momentum is measured in units of MeV/c and the energy is measured in MeV, how do the momentum and energy compare as the energy gets very large (i.e.) much larger than the rest mass of the particle)?
  1. The momentum gets much larger than the energy.
  2. They become nearly equal.
  3. The energy becomes much larger than the momentum.
  4. They oscillate back and forth (this is the source of neutrino oscillations).
  5. It depends on the potential energy of the system.



No matter how much energy I add to an object, I can't get it to go faster than the speed of light (or even as fast as the speed if light if it has mass). Is its momentum similarly limited?
  1. Yes. Since p=mv and the mass doesn't change, the momentum can only get so big.
  2. No, it can be as big as you want.
  3. It can grow as big as you want by increasing the rest mass, even though the speed is limited.
  4. Yes, it is limited because the total energy can't exceed mc2.
  5. It depends on more information than you have supplied.



A particle's relativistic kinetic energy K is the difference between its total energy and the energy it has at rest by virtue of its mass m. How does the relativistic kinetic energy compare with the non-relativistic kinetic energy?
  1. They're always equal.
  2. The relativistic kinetic energy is always larger.
  3. The non-relativistic kinetic energy is always larger.
  4. Sometimes one is larger and sometimes the other is larger.



In a fission reaction, a large nucleus breaks into smaller pieces, releasing energy in the process. How does the total mass of the final particles compare to the initial mass of the nucleus?
  1. The final particles have more mass.
  2. The final particles have the same mass.
  3. The final particles have less total mass.
  4. The mass of the real particles goes up, but the anti-particles have negative mass keeping the sum to be the same.
  5. It depends on the nucleus.



In a fusion reaction, two or more nuclei are combined to form a larger nucleus. Nuclei with atomic numbers less than that of iron can usually be fused in a way that releases energy. In these cases, how would be mass of the resultant nucleus (and any emitted particles) compare to that of the original nuclei?
  1. The final and initial masses would be the same.
  2. The final mass would be larger.
  3. The final mass would be smaller.
  4. The final mass could be larger or smaller.
  5. none of these