Date: Name: Ontario Virtual KU TI C A School 10 10 SPH4U UNIT 5 QUIZ - MODERN PHYSICS Part A - Knowledge and Understanding [10 marks] Multiple Choice - Use a capital letter that best completes the statement or answers the question [10 marks] 1. The rest energy, in joules, of an electron of mass 9.11 x 10 31 kg is a. 5.1 x 105 J d. 3.0 x 10 39 J b. 8.2 x 10-14 J 1.0 x 10 47 J c. 2.7 x 10 22 J Simultaneous events in one frame of reference mean that the event will be a. simultaneous in all frames of reference b. only simultaneous if both frames are moving in the same direction . only simultaneous if both frames are moving in the opposite direction d. only simultaneous in the same frame of reference e. simultaneity cannot be determined 3. A horizontal meter stick travels past you at 0.75c. You will measure the stick to be a. 1.51 m 1.00 m 0.66 m 0.56 m e. 0.44 m An electron and a positron, each of mass 9.11 x 10 31 kilogram, are in the same general vicinity and have very small initial speeds. They then annihilate each other, producing two photons. What is the approximate energy of each emerging photon? a. 0.51 MeV b. 2.0 MeV c. 4.0 MeV d. 6.6 MeV e. It cannot be determined unless the frequency of the photon is known 5. As the sun "burns" in a nuclear fusion reaction , it is a. gaining mass b. recycling mass energy levels c. losing mass d. neither gaining of losing mass e. none of the above 6. Time is dependent on the observer b. simultaneous in all cases C. absolute d. the same for different observers e. never changing 7. A discrete bundle of energy is a a. Photon b. Electron c. Positron d. Muon e. Energon