Question 1

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+ +   B

Question 2

A model for how repulsive forces between two particles can be mediated by a third particle would be

Accepted Answer

A) A person on a skateboard pushing against a wall. 
B) two people in two canoes throwing a ball back and forth. 
C) two people in two canoes each pulling on one end of a rope. 
D) two people in two skateboards giving each other a shove. 
E) two people in two skateboards each pulling on one end of a rope. 
A) A person on a skateboard pushing against a wall. 
B) two people in two canoes throwing a ball back and forth. 
C) two people in two canoes each pulling on one end of a rope. 
D) two people in two skateboards giving each other a shove. 
E) two people in two skateboards each pulling on one end of a rope. B

Question 3

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)    . B

Question 4

The minimum energy needed to produce a positron is

Accepted Answer

A) 3 MeV 
B) 2 MeV 
C) 1 MeV 
D) 4 MeV 
E) 0.51 MeV 
A) 3 MeV 
B) 2 MeV 
C) 1 MeV 
D) 4 MeV 
E) 0.51 MeV

Question 5

Which one of the following is not true of neutrinos?

Accepted Answer

A) They have no charge. 
B) They have no spin. 
C) One type of neutrino may change into another type of neutrino. 
D) They are leptons. 
E) They do not take part in strong nuclear interactions. 
A) They have no charge. 
B) They have no spin. 
C) One type of neutrino may change into another type of neutrino. 
D) They are leptons. 
E) They do not take part in strong nuclear interactions.

Question 6

All particles can be classified into

Accepted Answer

A) Leptons and quarks 
B) Hadrons and leptons 
C) Baryons and leptons 
D) Mesons and Baryons 
A) Leptons and quarks 
B) Hadrons and leptons 
C) Baryons and leptons 
D) Mesons and Baryons

Question 7

The particle reaction  
Cannot occur because

Accepted Answer

A) electric charge is not conserved. 
B) strangeness is not conserved. 
C) baryon number is not conserved. 
D) all of the above are not conserved. 
E) both (a)and (b)above are not conserved. 
A) electric charge is not conserved. 
B) strangeness is not conserved. 
C) baryon number is not conserved. 
D) all of the above are not conserved. 
E) both (a)and (b)above are not conserved.

Question 8

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 9

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 10

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 11

A K0 particle at rest decays into a π+ and a π−.What will be the speed of each of the pions? The mass of the K0 is 497.7 MeV/c2 and the mass of each π is 139.6 MeV/c2.

Accepted Answer

Question 12

If the quark content of the proton,p,is uud,the quark content of the antiproton,  
Is

Accepted Answer

A) uud. 
B) udd. 
C)    . 
D)    . 
E)    . 
A) uud. 
B) udd. 
C)    . 
D)    . 
E)    .

Question 13

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 14

The rest-energy of the Z0 boson is 96 GeV.Using this information,find the maximum length of time a virtual Z0 can exist,in accordance with the uncertainty principle  
)(1 eV = 1.6 × 10−19 J. )

Accepted Answer

A) 3.4 × 10−27 s 
B) 7.5 × 10−30 s 
C) 2.4 × 10−24 s 
D) 1.9 × 10−21 s 
E) 6.3 × 10−5 s 
A) 3.4 × 10−27 s 
B) 7.5 × 10−30 s 
C) 2.4 × 10−24 s 
D) 1.9 × 10−21 s 
E) 6.3 × 10−5 s

Question 15

Which of the following decays violates conservation of lepton number?

Accepted Answer

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

Question 16

The following reaction can occur by the strong interaction: π0 + n → K+ + Σ−.If the quark composition of the n is (udd),the π° is (  
),and the composition of the K+ is (  
),find the quark composition of the Σ−.

Accepted Answer

A) sss 
B) uds 
C) dds 
D)    
E)    
A) sss 
B) uds 
C) dds 
D)    
E)

Question 17

Name at least one conservation law that prevents each of the following reactions:
A)π− + p → Σ+ + π°
B)p → π+ + π+ + π−

Accepted Answer

A)charge,

Question 18

According to the Hubble law,where H = 17 km/s/106 lightyears,what is the velocity of recession of a quasar at a distance of 2 billion lightyears from Earth?

Accepted Answer

A) 0.75 c 
B) 0.33 c 
C) 0.55 c 
D) 0.11 c 
E) 0.93 c 
A) 0.75 c 
B) 0.33 c 
C) 0.55 c 
D) 0.11 c 
E) 0.93 c

Question 19

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 20

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

Exam 46: Particle Physics and Cosmology

Which of the following reactions cannot occur?

A model for how repulsive forces between two particles can be mediated by a third particle would be

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

The minimum energy needed to produce a positron is

Which one of the following is not true of neutrinos?

All particles can be classified into

The particle reaction Cannot occur because

The three quarks in any baryon must all have different

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?

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

A K0 particle at rest decays into a π+ and a π−.What will be the speed of each of the pions? The mass of the K0 is 497.7 MeV/c2 and the mass of each π is 139.6 MeV/c2.

If the quark content of the proton,p,is uud,the quark content of the antiproton, Is

The rest-energy of the Z0 boson is 96 GeV.Using this information,find the maximum length of time a virtual Z0 can exist,in accordance with the uncertainty principle )(1 eV = 1.6 × 10−19 J. )

Which of the following decays violates conservation of lepton number?

The following reaction can occur by the strong interaction: π0 + n → K+ + Σ−.If the quark composition of the n is (udd),the π° is ( ),and the composition of the K+ is ( ),find the quark composition of the Σ−.

Name at least one conservation law that prevents each of the following reactions: A)π− + p → Σ+ + π° B)p → π+ + π+ + π−

According to the Hubble law,where H = 17 km/s/106 lightyears,what is the velocity of recession of a quasar at a distance of 2 billion lightyears from Earth?

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 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. )

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

Sound Waves

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

Applications of Nuclear Physics

Filters

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 K⁰ particle at rest decays into a π⁺ and a π⁻.What will be the speed of each of the pions? The mass of the K⁰ is 497.7 MeV/c² and the mass of each π is 139.6 MeV/c².

The rest-energy of the Z⁰ boson is 96 GeV.Using this information,find the maximum length of time a virtual Z⁰ can exist,in accordance with the uncertainty principle )(1 eV = 1.6 × 10−¹⁹ J. )

The following reaction can occur by the strong interaction: π⁰ + n → K⁺ + Σ⁻.If the quark composition of the n is (udd),the π° is ( ),and the composition of the K⁺ is ( ),find the quark composition of the Σ⁻.

Name at least one conservation law that prevents each of the following reactions: A)π⁻ + p → Σ⁺ + π° B)p → π⁺ + π⁺ + π⁻

According to the Hubble law,where H = 17 km/s/10⁶ lightyears,what is the velocity of recession of a quasar at a distance of 2 billion lightyears from Earth?

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. )