SPH4U UNIT 5 QUIZ MODERN PHYSICS 0 e 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! kg is a. S5.1x10] d. 3.0x107*] b. B2x10"] e. l.Ox 107%] c. 27x107%1] 2. Simultaneous events in one frame of reference mean that the event will be a. simultaneous in all frames of reference only simultaneous if both frames are moving in the same direction only simultaneous if both frames are moving in the opposite direction only simultaneous in the same frame of reference simultaneity cannot be determined B 0 3. A horizontal meter stick travels past you at (1.75c. You will measure the stick to be a. 1.5l m b. 1.00m c. 0(.66m d 0.56m e. (.44m 4. An electron and a positron, each of mass 9.11 x 107! 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 1s 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 a. 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. Energon8. Two spaceships are heading towards each other with speeds of 00.5. One ship shines a laser beam at the other. How will each ship see the light? Both will see the light travel at 0.5c. Both will see the light travel at . One ship will see the light at 1.5, the other will see the light travel at 0.5. Both will see the light travel at 0.75. ao TR 9. The following graph shows Millikan's data for V. (V) _ Hop determining the threshold frequency for a given material by varying the frequency of the incident light. Which of the following will change the threshold frequency, f;? 2 a. Use a different metal I Increase the light intensity Increase the light frequenc 0 . f(x 10" Hz) Decrease the l?ghtf:?ensit; 2 4\\6 & 1012 f = 14 Decrease the light frequency R=AR R " RS T 10. If an astronaut who has only aged 3 years returns to Earth 15 years later, how fast was his ship travelling? a. 020c b. 0.45c c. 0350c d. 0.98c e. 1.02c Application Neatly provide written responses I1. A car is moving at a rapid pace. It is approaching a garage with doors at either end. The proper length of the car is longer than the garage. As the car travels through the garage, describe what the driver would observe. Describe what would be seen by a stationary observer inside the garage. [3 marks] 12. A beam of radicactive particles travels at a speed of 2.5 x 10* m/s. The half-life of the particles in the beam is measured to be 1.4us by an outside observer. Determine the half-life of those particles when they are at rest with respect to the observer. [2 marks] 13. Imaginary element ) has an atomic number of 129 and an atomic mass of 345. Complete the nuclear equation for element Q) if it emits an alpha particle and daughter particle NQ. [3 marks] 14. Complete the following equation:**s:Np *u"Pu + + [2 marks]