Q&A Hero

Q: In all interactions __________ number is conserved.

Q: The __________ are force-carrying particles.

Q: A __________ does not interact via the strong interaction.

Q: __________ is the collective name given for particles that interact via the strong force.

Q: A particle with __________ obeys the Pauli exclusion principle.

Q: A __________ has half integral spin.

Q: A __________ has integral spin.

Q: If a 1 kg mass is completely converted into energy, the amount of energy released would be __________.

Q: If a twin goes on a trip in a high speed rocket ship, when she returns home she will be younger than her twin sister who did not go on the trip because of the special relativistic effect of __________.

Q: Because of their short lifetimes, very few muons that are produced in the upper atmosphere at high speeds should be observed at the surface of the earth. Yet we detect large numbers of muons at ground level because of the special relativistic effect of __________.

Q: Since the mass of an object is the same for all observers, it is a relativistically ____________ quantity.

Q: According to special relativity the __________ of a moving object is equal to .

Q: If you do an experiment on earth, and then do an identical experiment in a jet plane moving uniformly at a high speed, you get identical results from both experiments. This is an example of __________.

Q: The mass of an electron and its antiparticle, a positron, is 0.511 MeV/c2. In order to produce an electron-positron pair, a gamma ray must have an energy larger than 1.022 MeV because __________.

Q: When it comes near a heavy nucleus, a gamma ray, which is a high energy photon, can "disappear," and in its place there will be produced an electron and a positron, which both have mass. According to special relativity, this pair production is an example of __________.

Q: An electron and a positron, which are two massive particles, can annihilate when they come together to produce two photons, which have no mass. According to special relativity, this pair annihilation is an example of __________.

Q: Einstein's famous equation E0= mc2is a statement of __________.

Q: The prediction from special relativity that the length of a moving object will be shortened in the direction of motion is called __________.

Q: __________ is the prediction of special relativity that moving clocks run slow.

Q: Particles possessing half-integral spins are called _________ and particles with integral spins are called ________.a. quarks b. fermions c. bosonsd. antiquarks

Q: t and b quarks are nameda. truth and beautyb. up and downc. top and bottomd. Itchy and Scratchye. none of the above

Q: Quarks have electric charges of magnitudea. eb. 1/3 ec. 2/3 ed. 0e. none of the above

Q: The electrona. is an absolutely stable particle b. decays via the weak interaction c. has zero massd. is a lepton

Q: In interactions taking place by the weak force, which of the following quantities are conserved? a. electric charge b. baryon number c. mass-energy d. strangeness e. linear momentum f. angular momentum (spin)

Q: In interactions taking place by the strong force, which of the following quantities are conserved? a. electric charge b. baryon number c. mass-energy d. strangeness e. linear momentum f. angular momentum (spin)

Q: A particle that interacts via the strong force is a(n) a. lepton b. baryon c. meson d. intermediate (or gauge) boson e. hadron

Q: Quarks come in what flavors?a. up, down and strange b. charm, top and bottom c. red, green and blued. all of the above

Q: The positrona. is an antielectronb. was the first antimatter particle discoveredc. is the same as a protond. all of the above

Q: Which of the following are notrelativistically invariant quantities?a. the speed of light, c b. time c. massd. energy

Q: Which of the following is considered anitmatter?a. u b. e- c. e+d. d

Q: Mesons are composed ofa. antiquarks b. quark-antiquark pairs c. quarksd. three-quark combinations

Q: Which of the following particle is unaffected by the Strong Force?a. protons b. neutrons c. mesonsd. gauge bosons

Q: The spins of all known particles are either integral or half-integral multiples ofa. the baryon number b. Plank's constant c. the Gravitational constantd. the speed of light

Q: Which of the following is not a fundamental force of nature:a. strong nuclear force b. electroweak force c. weak nuclear forced. electromagnetic interaction

Q: A quantum number for a quark isa. strangenessb. beautyc. charmd. truthe. all of the above

Q: Quarks are bound together in hadrons bya. the strong force b. the weak force c. intermediate (or gauge) bosonsd. the color force

Q: The fundamental particles that are the building blocks of hadrons are a. leptons b. baryons c. mesons d. intermediate (or gauge) bosons e. quarks

Q: Steven Weinberg, Abdus Salam, and Sheldon Glashow shared the 1979 Nobel prize in physics for their development of a(n) a. electroweak theory b. GUT c. quark theory d. generalized theory of relativity e. theory of strangeness

Q: A model for combining the electromagnetic, weak and strong nuclear interactions into a single basic force is a(n) a. electroweak theory b. GUT c. quark theory d. generalized theory of relativity e. theory of strangeness

Q: Conservation of ____________ is observed in strong and electromagnetic interactions but not in weak interactions. a. baryon number b. lepton number c. strangeness d. charm e. beauty

Q: Conservation of ___________ is observed in all interactions. a. baryon number b. lepton number c. strangeness d. charm e. beauty

Q: A force-carrying particle is a(n) a. lepton b. baryon c. meson d. intermediate (or gauge) boson e. hadron

Q: Why do strange particles have long lifetimes compared to other strongly interacting particles?a. No one knowsthis is why they are called "strange."b. They only decay via the weak interaction.c. They are more massive.d. none of the above

Q: A spin-1/2 particle that does not interact via the strong interaction is a(n) a. lepton b. baryon c. meson d. intermediate (or gauge) boson e. hadron

Q: The top quarka. is the only quark not yet detected experimentallyb. has been shown not to existc. was discovered at Fermilabd. none of the above

Q: Gluonsa. are carriers of the color forceb. posses color chargec. can interact with each other via the color forced. can form glueballse. all of the above

Q: The color force between quarks is carried bya. mesonsb. the strong forcec. leptonsd. gluonse. none of the above

Q: How many quark colors are there?a. 1b. 3 c. 6d. none of the above

Q: How many quark flavors are there?a. 1 b. 3 c. 6d. none of the above

Q: What is the quark structure of an electron?a. uudb. uddc. uuud. ddde. the question does not make sense

Q: What is the quark structure of a neutron?a. uudb. uddc. uuud. ddde. the question does not make sense

Q: What's the quark structure of an antiproton?a. ddu b. bbt c. d. none of the above

Q: What is the quark structure of a proton? a. uud b. udd c. uuu d. ddd e. the question does not make sense

Q: Electrons are "spin one-half," photons area. also spin one-half b. spin zero c. spin oned. none of the above

Q: "Half integral spin" means spina. 1/2 b. 1/2, 1, 3/2, 2, ... c. 1/2, 3/2, 5/2, ...d. none of the above

Q: A particle with ____________ obeys the Pauli exclusion principle. a. zero rest mass b. very high energy c. half integral spin d. integral spin e. charm

Q: A particle with a half integer spin is a a. boson b. lepton c. fermion d. hadron e. muon

Q: A particle with an integer spin is a a. boson b. lepton c. fermion d. hadron e. muon

Q: A fundamental force in nature is thea. strong interactionb. weak interactionc. electromagnetic interactiond. gravitational interactione. all of the above

Q: If a 1 kg mass is completely converted into energy, the amount of energy released would bea. 0.333 Jb. 1 Jc. 3 x 108Jd. 9 x 1016Je. none of the above

Q: If a twin goes on a trip in a high speed rocket ship, when she returns home she will be younger than her twin sister who did not go on the trip because ofa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: From the point of view of a muon produced high in the atmosphere, the reason it can get to the ground before it decays is because a. relativity gives it extra time to get there b. of the uncertainty principle c. it is a short distance to the ground d. relativity shortens the distance to the ground

Q: From the point of view of an observer on the earth, a muon produced high in the atmosphere can reach the ground before decaying because a. relativity gives it extra time to get there b. of the uncertainty principle c. it is a short distance to the ground d. relativity shortens the distance to the ground

Q: Because of their short lifetimes, very few muons that are produced in the upper atmosphere at high speeds should be observed at the surface of the earth. Yet we detect large numbers of muons at ground level because ofa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: At speeds approaching the speed of light, the kinetic energy of a moving object is equal toa. 1/2 mv2b. 1/2 mc2c. d. e. none of the above

Q: If you do an experiment on earth, and then do an identical experiment in a jet plane moving uniformly at a high speed, you get identical results from both experiments. This is an example ofa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: The rest energy of an electron and its antiparticle, a positron, is 0.511 MeV. In order to produce an electron-positron pair, a gamma ray must have an energy larger than 1.022 MeV because ofa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: What is the symbol for a photon?a. n b. c. d. none of the above

Q: When it comes near a heavy nucleus, a gamma ray, which is a high energy photon, can "disappear," and in its place there will be produced an electron and a positron, which both have mass. This pair production is an example ofa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: The notation used to represent an antiparticle isa. the particle symbol with a bar over itb. e+, in the case of the positronc. m+, in the case of the antimuond. all of the above

Q: When a particle and antiparticle meet, they are said to annihilateeach other. What does this mean?a. They explode into tiny fragments.b. They are destroyed, and turned into an equivalent amount of energy.c. They merge and simply disappear.d. none of the above

Q: What is different between a particle and its antiparticle?a. opposite electric chargeb. opposite strangenessc. opposite charmd. all of the above

Q: An electron and a positron, which are two massive particles, can annihilate when they come together to produce two photons, which have no mass. This pair annihilation is an example ofa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: What is the mass of an electron in MeV/c2?a. 0.511 MeV/c2b. 105.7 MeV/c2c. 1777 MeV/c2d. none of the above

Q: Einstein's famous equation E0= mc2is a statement ofa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: The prediction from special relativity that the length of a moving object will be shortened in the direction of motion isa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: The prediction of special relativity that moving clocks run slow isa. time dilationb. length contractionc. the equivalence of mass and energyd. the principle of relativitye. none of the above

Q: Two observers, A and B, move relative to each other. A claims B's clocks run slow. In this case, B will claim A's clocksa. run fast b. run slow, too c. are no goodd. none of the above

Q: If you are driving down a highway at 65 mph with your headlights on, the speed of the light emitted from your headlights as seen by a person standing on the side of the road isa. cb. c+ 65 mphc. slightly greater than cd. none of the above

Q: What is the symbol for a neutrino?a. n b. c. d. none of the above