Deck 31: Particle Collisions, Mediating Photons, and Quark Structures: Exploring the Fundamentals of Physics

Question 1

The quark structure of the neutron is udd.What is the quark structure of the antineutron?

A)

B) ddu
C)

D) udd,since the neutron is its own antiparticle

Answer 1

Question 2

Assuming the Hubble constant is (21 km/s)/(10⁶ ly),what is the recession speed of a galaxy 300 million parsecs away? (1 parsec = 3.26 ly)

A) 4200 km/s
B) 21,000 km/s
C) 640 km/s
D) 7000 km/s

Answer 2

21,000 km/s

Question 3

The strong force is mediated by

A) the gluon.
B) the W^- boson.
C) the W⁺ boson.
D) All of these choices.

Answer 3

the gluon.

Question 4

Which of the following forces is the strongest at near distances?

A) gravitational
B) weak nuclear
C) strong nuclear
D) electromagnetic

Question 5

The following reaction can occur by the strong interaction: π⁰ + n → K⁺ + Σ^-.If the quark composition of the n is (udd),the π ⁰ is And the composition of the K⁺ is ,what is the quark composition of the Σ^-?

A) uds
B) dds
C) sss
D)

Question 6

If a K⁰ meson at rest decays in 0.90 × 10−¹⁰ s,how far will a K⁰ meson moving at 0.95c travel through a bubble chamber? (c = 3.00 × 10⁸ m/s)

A) 2.6 cm
B) 8.2 cm
C) 9.3 cm
D) 13 cm

Question 7

The microwave background radiation:

A) represents the leftover glow from the Big Bang.
B) had its slight non-uniformity measured by COBE.
C) was discovered by Penzias and Wilson.
D) All of the above.

Question 8

Processes in which one type of quark is converted into another type of quark involve which force?

A) electromagnetic
B) strong force
C) weak force
D) gravitational

Question 9

Of the quarks u,d,c,s,t,and b,which have positive fractional electronic charge?

A) u,d,c
B) d,s,b
C) s,t,b
D) u,c,t

Question 10

The exchange of mediating photons can produce

A) neither a repulsive nor an attractive force.
B) either a repulsive or an attractive force.
C) a repulsive force.
D) an attractive force.

Question 11

A proton and antiproton each with total energy 800 GeV collide head-on.What is the total energy (particles + energy)released?

A) zero
B) 800 GeV
C) 400 GeV
D) 1600 GeV

Question 12

Which of these particles has the least mass?

A) electron neutrino
B) muon
C) electron
D) pion

Question 13

Of the following mesons,which is its own antiparticle?

A) K^-
B) φ
C) π⁺
D) none of those given

Question 14

What following quantity is conserved in the following reaction:
?

A) charge
B) lepton number
C) baryon number
D) All of the above.

Question 15

The cosmic background radiation appears compatible with a blackbody source at what temperature?

A) 0.0003 K
B) 3 K
C) 300 K
D) 0.03 K

Question 16

The constituent quarks of the proton are uud.What are the charges on u and d?

A)

B)

C)

D)