Question 1

The three quarks in any baryon must all have different

Accepted Answer

A)  baryon number. 
B)  color charge. 
C)  electric charge. 
D)  lepton number. 
E)  spin. 
A)  baryon number. 
B)  color charge. 
C)  electric charge. 
D)  lepton number. 
E)  spin.

Question 2

The law of conservation of baryon number is that

Accepted Answer

A)  the total number of baryons and leptons is conserved. 
B)  the total number of baryons is conserved. 
C)  the (number of baryons) − (number of antibaryons) is conserved. 
D)  the total number of quarks is conserved. 
E)  the (number of baryons) + (number of antibaryons) is conserved. 
A)  the total number of baryons and leptons is conserved. 
B)  the total number of baryons is conserved. 
C)  the (number of baryons) − (number of antibaryons) is conserved. 
D)  the total number of quarks is conserved. 
E)  the (number of baryons) + (number of antibaryons) is conserved.

Question 3

An electron and a positron (antielectron), both nearly at rest, collide. What particle(s) is(are) produced?

Accepted Answer

A)  One photon of energy 1.02 MeV 
B)  Two photons of energy 511 keV 
C)  A pi-meson 
D)  A K-meson and an anti-neutrino 
A)  One photon of energy 1.02 MeV 
B)  Two photons of energy 511 keV 
C)  A pi-meson 
D)  A K-meson and an anti-neutrino

Question 4

A photon with an energy of Eγ = 2.090 0 GeV creates a proton-antiproton pair in which the proton has a kinetic energy of 95.0 MeV. What is the kinetic energy of the antiproton? (mpc2 = 938.3 MeV)

Accepted Answer

Question 5

Which of the following reactions cannot occur?

Accepted Answer

A)  n → p + e− +
  
B)  p + n → p + p +
  
C)  μ− → e− +
  +
  μ 
D)  π− → μ− + νμ 
E)  π+ → μ+ +
  
A)  n → p + e− +
  
B)  p + n → p + p +
  
C)  μ− → e− +
  +
  μ 
D)  π− → μ− + νμ 
E)  π+ → μ+ +

Question 6

Which of the following particle reactions cannot occur?

Accepted Answer

A)  p + p → p + p + p +
  
B)  p +
  → 2γ 
C)  π+ + p → K+ + Σ+ 
D)  γ + p → n + π0 
E)  e− + e+ → 2γ 
A)  p + p → p + p + p +
  
B)  p +
  → 2γ 
C)  π+ + p → K+ + Σ+ 
D)  γ + p → n + π0 
E)  e− + e+ → 2γ

Question 7

According to string theory, six space-time dimensions cannot be measured except as quantum numbers of internal particle properties because they are curled up in size of the order of

Accepted Answer

A)  10−35 m. 
B)  10−15 m. 
C)  10−10 m. 
D)  10−8 m. 
E)  10−3 m. 
A)  10−35 m. 
B)  10−15 m. 
C)  10−10 m. 
D)  10−8 m. 
E)  10−3 m.

Question 8

The acceleration (or deceleration) of the expansion of the universe is determined by

Accepted Answer

A)  the standard matter, baryons and leptons. 
B)  the dark matter in the universe. 
C)  the dark energy in the universe. 
D)  all of the above. 
E)  only (b) and (c) above. 
A)  the standard matter, baryons and leptons. 
B)  the dark matter in the universe. 
C)  the dark energy in the universe. 
D)  all of the above. 
E)  only (b) and (c) above.

Question 9

In the standard model of the expansion of the universe, the total energy of a standard mass m is assumed to be zero. When we solve the resulting energy equation for the critical mass density of the universe, we find that the critical mass density is given by

Accepted Answer

A) 
  . 
B) 
  . 
C) 
  . 
D) 
  . 
E) 
  . 
A) 
  . 
B) 
  . 
C) 
  . 
D) 
  . 
E) 
  .

Question 10

The strong nuclear interaction has a range of approximately 0.70 × 10−15 m. It is thought that an elementary particle is exchanged between the protons and neutrons, leading to an attractive force. Utilize the uncertainty principle   to estimate the mass of the elementary particle if it moves at nearly the speed of light.

Accepted Answer

A)  140 MeV/c2, a pion 
B)  511 keV/c2, an electron 
C)  96 GeV/c2, a Z boson 
D)  500 MeV/c2, a K meson 
E)  106 MeV/c2, a muon 
A)  140 MeV/c2, a pion 
B)  511 keV/c2, an electron 
C)  96 GeV/c2, a Z boson 
D)  500 MeV/c2, a K meson 
E)  106 MeV/c2, a muon

Question 11

In this course we have seen that baryons have inertial and gravitational mass, intrinsic angular momentum, and other internal properties that have been given names like baryon number, strangeness, charm, etc. The Standard Model's explanation for these properties of baryons is that

Accepted Answer

A)  the baryons are states of something more elementary that can exist in multiple quantum states. 
B)  the leptons are states of something more elementary that can exist in multiple quantum states. 
C)  photons are states of something more elementary that can exist in multiple quantum states. 
D)  according to the Heisenberg Uncertainty Principle quantum numbers are indeterminate. 
E)  quarks are states of something more elementary that can exist in multiple quantum states. 
A)  the baryons are states of something more elementary that can exist in multiple quantum states. 
B)  the leptons are states of something more elementary that can exist in multiple quantum states. 
C)  photons are states of something more elementary that can exist in multiple quantum states. 
D)  according to the Heisenberg Uncertainty Principle quantum numbers are indeterminate. 
E)  quarks are states of something more elementary that can exist in multiple quantum states.

Question 12

The attractive force between protons and neutrons in the nucleus is brought about by the exchange of a virtual pi-meson (mπ = 140 MeV/c2). Estimate the longest time a virtual π0 can exist, in accordance with the uncertainty principle   . (1 eV = 1.6 × 10−19 J.)

Accepted Answer

A)  2.4 × 10−24 s 
B)  6.9 × 10−27 s 
C)  3.3 × 10−18 s 
D)  2.4 × 10−21 s 
E)  1.6 × 10−19 s 
A)  2.4 × 10−24 s 
B)  6.9 × 10−27 s 
C)  3.3 × 10−18 s 
D)  2.4 × 10−21 s 
E)  1.6 × 10−19 s

Question 13

The omega-minus particle decays   with the X0 and the π− eventually decaying into stable baryon(s) and lepton(s). Utilizing conservation laws, which of the following is the correct accounting of the decay products?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 14

A proton and an antiproton each with total energy of 400 GeV collide head-on. What is the total energy (particles + energy) released?

Accepted Answer

A)  zero 
B)  400 Gev 
C)  800 GeV 
D)  1 600 GeV 
E)  2 400 GeV 
A)  zero 
B)  400 Gev 
C)  800 GeV 
D)  1 600 GeV 
E)  2 400 GeV

Exam 46: Particle Physics and Cosmology

The three quarks in any baryon must all have different

The law of conservation of baryon number is that

An electron and a positron (antielectron), both nearly at rest, collide. What particle(s) is(are) produced?

A photon with an energy of Eγ = 2.090 0 GeV creates a proton-antiproton pair in which the proton has a kinetic energy of 95.0 MeV. What is the kinetic energy of the antiproton? (mpc2 = 938.3 MeV)

Which of the following reactions cannot occur?

Which of the following particle reactions cannot occur?

According to string theory, six space-time dimensions cannot be measured except as quantum numbers of internal particle properties because they are curled up in size of the order of

The acceleration (or deceleration) of the expansion of the universe is determined by

In the standard model of the expansion of the universe, the total energy of a standard mass m is assumed to be zero. When we solve the resulting energy equation for the critical mass density of the universe, we find that the critical mass density is given by

In this course we have seen that baryons have inertial and gravitational mass, intrinsic angular momentum, and other internal properties that have been given names like baryon number, strangeness, charm, etc. The Standard Model's explanation for these properties of baryons is that

The attractive force between protons and neutrons in the nucleus is brought about by the exchange of a virtual pi-meson (mπ = 140 MeV/c2). Estimate the longest time a virtual π0 can exist, in accordance with the uncertainty principle . (1 eV = 1.6 × 10−19 J.)

The omega-minus particle decays with the X0 and the π− eventually decaying into stable baryon(s) and lepton(s). Utilizing conservation laws, which of the following is the correct accounting of the decay products?

A proton and an antiproton each with total energy of 400 GeV collide head-on. What is the total energy (particles + energy) released?

Physics and Measurement

Motion in One Dimension

Vectors

Motion in Two Dimensions

The Laws of Motion

Circular Motion and Other Applications of Newtons Laws

Energy of a System

Conservation of Energy

Linear Momentum and Collisions

Rotation of a Rigid Object About a Fixed Axis

Angular Momentum

Static Equilibrium and Elasticity

Universal Gravitation

Fluid Mechanics

Oscillatory Motion

Wave Motion

Superposition and Standing Waves

Temperature

The First Law of Thermodynamics

The Kinetic Theory of Gases

Heat Engines, Entropy, and the Second Law of Thermodynamics

Electric Fields

Gausss Law

Electric Potential

Capacitance and Dielectrics

Current and Resistance

Direct-Current Circuits

Magnetic Fields

Sources of the Magnetic Field

Faradays Law

Inductance

Alternating-Current Circuits

Electromagnetic Waves

The Nature of Light and the Principles of Ray Optics

Image Formation

Wave Optics

Diffraction Patterns and Polarization

Relativity

Introduction to Quantum Physics

Quantum Mechanics

Atomic Physics

Molecules and Solids

Nuclear Structure

Filters

A photon with an energy of Eγ = 2.090 0 GeV creates a proton-antiproton pair in which the proton has a kinetic energy of 95.0 MeV. What is the kinetic energy of the antiproton? (m_pc² = 938.3 MeV)

The attractive force between protons and neutrons in the nucleus is brought about by the exchange of a virtual pi-meson (mπ = 140 MeV/c²). Estimate the longest time a virtual π⁰ can exist, in accordance with the uncertainty principle . (1 eV = 1.6 × 10−¹⁹ J.)

The omega-minus particle decays with the X⁰ and the π⁻ eventually decaying into stable baryon(s) and lepton(s). Utilizing conservation laws, which of the following is the correct accounting of the decay products?