Question 1

What is the minimum energy required to produced a proton-antiproton pair? A proton has a rest mass of 938 MeV/c².

Accepted Answer

The minimum energy required to produce a proton-antiproton pair is twice the rest mass energy of a proton, which is 2 * 938 MeV = 1876 MeV.

Question 2

What is the speed of a proton with kinetic energy of 2 GeV?

Accepted Answer

The speed of a proton with a kinetic energy of 2 GeV is approximately 0.95c, considering relativistic effects and the rest mass energy of the proton (approximately 938 MeV).

Question 3

What is the speed of a 2-MeV electron?

Accepted Answer

The speed of a 2-MeV electron is approximately 0.98 times the speed of light (c), as calculated using relativistic energy-momentum relations.

Question 4

What is the temperature corresponding to a thermal energy of 50 GeV, the particle energy in the accelerator at SLAC?

Accepted Answer

The temperature corresponding to a thermal energy can be calculated using the formula E = kT, where E is the energy, k is the Boltzmann constant, and T is the temperature. For 50 GeV, the temperature is approximately 3.9 × 10¹⁴ K.

Question 5

How far is the galaxy from the Earth if it recedes from Earth at a speed v = 0.5 c ? (Use H₀ = 0.022 m/s · lightyear for Hubble's constant.)

Accepted Answer

The distance to the galaxy can be calculated using Hubble's Law: v = H₀ × d. Solving for d gives d = v / H₀. Substituting v = 0.5c (where c is the speed of light, approximately 3 × 10⁸ m/s) and H₀ = 0.022 m/s · lightyear, we find d ≈ 6.8 × 10⁹ lightyears.

Question 6

A certain galaxy is 2.7 x 10⁹ lightyears from the Earth. How fast is it receding from us? (Use H₀ = 0.022 m/s · lightyear for Hubble's constant.)

Accepted Answer

The answer of A certain galaxy is 2.7 x 10⁹...

Question 7

How much energy is available when a 30 GeV electron strikes a stationary proton?

Accepted Answer

The answer of How much energy is available when a...

Question 8

How much energy is available when two 30-GeV electrons collide head-on?

Accepted Answer

When two particles collide head-on, the total energy available in the center of mass frame is the sum of their energies, so 30 GeV + 30 GeV = 60 GeV.

Question 9

What is the minimum energy required to produced an electron-position pair? A electron has a rest mass of 0.511 MeV/c².

Accepted Answer

The minimum energy required to produce an electron-position pair is twice the rest mass of an electron, which is 1.022 MeV.

Question 10

The rest energy of ? meson is about 140 MeV. What is the range of strong force? (h = 6.63 × 10^-34 J·s)

Accepted Answer

The range of the strong force can be estimated using the uncertainty principle and the rest energy of the meson. The range is approximately given by ħc/E, where ħ is the reduced Planck's constant and E is the energy. Using the given energy of 140 MeV, the range is approximately 1.4 × 10^-15 m.

Question 11

The rest energy of a Z⁰ boson is 91 GeV. Using the uncertainty principle, what is the approximate interaction time when it mediates weak interaction? (h = 6.63 × 10^-34 J·s)

Accepted Answer

The uncertainty principle states that the uncertainty in the energy of a particle is related to the uncertainty in the time of its interaction by the equation ΔEΔt ≥ h/4π. In this case, the uncertainty in the energy of the Z⁰ boson is ΔE = 91 GeV, and the uncertainty in the time of its interaction is Δt. Solving for Δt, we get Δt ≥ h/4πΔE = 6.63 × 10^-34 J·s / (4π × 91 GeV) = 7.2 × 10^-27 s.

Question 12

A ?⁺ and ?^- at rest annihilate to produce two gamma rays that fly in the opposite directions. What is the wavelength of each gamma ray? The rest energy of a muon is 106 MeV and H = 6.63 × 10^-34 J·s.

Accepted Answer

The correct answer is A.The total energy of the two gamma rays is equal to the rest energy of the muon, which is 106 MeV. The wavelength of each gamma ray is given by the equation:$$\lambda = \frac{hc}{E}$$where h is Planck's constant, c is the speed of light, and E is the energy of the gamma ray.Substituting the given values into the equation, we get:$$\lambda = \frac{(6.63 	imes 10^{-34} 	ext{ J$\cdot$s})(3 	imes 10^8 	ext{ m/s})}{106 	imes 1.6 	imes 10^{-13} 	ext{ J}} = 1.17 	imes 10^{-14} 	ext{ m}$$

Question 13

The rest energy of W⁺ boson is about 80 GeV. What is the range of weak interaction? (h = 6.63 × 10^-34 J·s)

Accepted Answer

The range of the weak interaction is approximately given by the Compton wavelength of the W boson, which is inversely proportional to its mass. Using the relation λ = ħ/(mc), where ħ is the reduced Planck's constant and mc is the energy equivalent of the mass (80 GeV), the range is approximately 2.5 × 10^-18 m.

Question 14

Protons are baryons made up of three quarks.

Accepted Answer

Protons are baryons, which are a type of hadron, and they are composed of three quarks: two up quarks and one down quark.

Question 15

The reaction p + p ? p + ?⁺ + ? is allowed.

Accepted Answer

The reaction p + p → p + π⁺ + n is not allowed because it violates charge conservation. The initial state has a charge of +2 (from two protons), while the final state has a charge of +3 (from a proton and a positively charged pion).

Question 16

The reaction e⁺ + ?⁰ ? p + v_e is not allowed.

Accepted Answer

The reaction violates the conservation of charge and baryon number. An electron-positron pair cannot produce a proton and a neutrino without additional particles to balance these conservation laws.

Question 17

The K^- meson, with quark composition $ {s }\overline{u} $ , has strangeness number S = +1.

Accepted Answer

The K^- meson has a strange quark (s) which contributes a strangeness number of -1, not +1.

Question 18

The D⁺meson, with quark composition C = +1. $ c \bar{d} $ , has charm number

Accepted Answer

The D⁺ meson is composed of a charm quark (c) and an anti-down quark ($\bar{d}$), giving it a charm number of +1 due to the presence of the charm quark.

Question 19

Scientists were led to postulate the existence of the neutrino in order to

Accepted Answer

The neutrino was postulated to account for the missing energy and momentum in beta decay, ensuring the conservation laws were upheld.

Question 20

Which one of the following particles can interact with all 4 of the known forces?

Accepted Answer

The anti-proton, like the proton, can interact with all four fundamental forces: gravitational, electromagnetic, weak nuclear, and strong nuclear forces.

Quiz 9: A Universe of Particles

What is the minimum energy required to produced a proton-antiproton pair? A proton has a rest mass of 938 MeV/c².

What is the speed of a proton with kinetic energy of 2 GeV?

What is the speed of a 2-MeV electron?

What is the temperature corresponding to a thermal energy of 50 GeV, the particle energy in the accelerator at SLAC?

How far is the galaxy from the Earth if it recedes from Earth at a speed v = 0.5 c ? (Use H₀ = 0.022 m/s · lightyear for Hubble's constant.)

A certain galaxy is 2.7 x 10⁹ lightyears from the Earth. How fast is it receding from us? (Use H₀ = 0.022 m/s · lightyear for Hubble's constant.)

How much energy is available when a 30 GeV electron strikes a stationary proton?

How much energy is available when two 30-GeV electrons collide head-on?

What is the minimum energy required to produced an electron-position pair? A electron has a rest mass of 0.511 MeV/c².

The rest energy of ? meson is about 140 MeV. What is the range of strong force? (h = 6.63 × 10^-34 J·s)

The rest energy of a Z⁰ boson is 91 GeV. Using the uncertainty principle, what is the approximate interaction time when it mediates weak interaction? (h = 6.63 × 10^-34 J·s)

A ?⁺ and ?^- at rest annihilate to produce two gamma rays that fly in the opposite directions. What is the wavelength of each gamma ray? The rest energy of a muon is 106 MeV and H = 6.63 × 10^-34 J·s.

The rest energy of W⁺ boson is about 80 GeV. What is the range of weak interaction? (h = 6.63 × 10^-34 J·s)

Protons are baryons made up of three quarks.

The reaction p + p ? p + ?⁺ + ? is allowed.

The reaction e⁺ + ?⁰ ? p + v_e is not allowed.

The K^- meson, with quark composition ${s }\overline{u}$ , has strangeness number S = +1.

The D⁺meson, with quark composition C = +1. $c \bar{d}$ , has charm number

Scientists were led to postulate the existence of the neutrino in order to

Which one of the following particles can interact with all 4 of the known forces?

Quiz 9: A Universe of Particles

What is the minimum energy required to produced a proton-antiproton pair? A proton has a rest mass of 938 MeV/c2.

What is the speed of a proton with kinetic energy of 2 GeV?

What is the speed of a 2-MeV electron?

What is the temperature corresponding to a thermal energy of 50 GeV, the particle energy in the accelerator at SLAC?

How far is the galaxy from the Earth if it recedes from Earth at a speed v = 0.5 c ? (Use H0 = 0.022 m/s · lightyear for Hubble's constant.)

A certain galaxy is 2.7 x 109 lightyears from the Earth. How fast is it receding from us? (Use H0 = 0.022 m/s · lightyear for Hubble's constant.)

How much energy is available when a 30 GeV electron strikes a stationary proton?

How much energy is available when two 30-GeV electrons collide head-on?

What is the minimum energy required to produced an electron-position pair? A electron has a rest mass of 0.511 MeV/c2.

The rest energy of ? meson is about 140 MeV. What is the range of strong force? (h = 6.63 × 10-34 J·s)

The rest energy of a Z0 boson is 91 GeV. Using the uncertainty principle, what is the approximate interaction time when it mediates weak interaction? (h = 6.63 × 10-34 J·s)

A ?+ and ?- at rest annihilate to produce two gamma rays that fly in the opposite directions. What is the wavelength of each gamma ray? The rest energy of a muon is 106 MeV and H = 6.63 × 10-34 J·s.

The rest energy of W+ boson is about 80 GeV. What is the range of weak interaction? (h = 6.63 × 10-34 J·s)

Protons are baryons made up of three quarks.

The reaction p + p ? p + ?+ + ? is allowed.

The reaction e+ + ?0 ? p + ve is not allowed.

The K- meson, with quark composition su‾ {s }\overline{u} su , has strangeness number S = +1.

The D+ meson, with quark composition C = +1. cdˉ c \bar{d} cdˉ , has charm number

Scientists were led to postulate the existence of the neutrino in order to

Which one of the following particles can interact with all 4 of the known forces?

What is the minimum energy required to produced a proton-antiproton pair? A proton has a rest mass of 938 MeV/c².

How far is the galaxy from the Earth if it recedes from Earth at a speed v = 0.5 c ? (Use H₀ = 0.022 m/s · lightyear for Hubble's constant.)

A certain galaxy is 2.7 x 10⁹ lightyears from the Earth. How fast is it receding from us? (Use H₀ = 0.022 m/s · lightyear for Hubble's constant.)

What is the minimum energy required to produced an electron-position pair? A electron has a rest mass of 0.511 MeV/c².

The rest energy of ? meson is about 140 MeV. What is the range of strong force? (h = 6.63 × 10^-34 J·s)

The rest energy of a Z⁰ boson is 91 GeV. Using the uncertainty principle, what is the approximate interaction time when it mediates weak interaction? (h = 6.63 × 10^-34 J·s)

A ?⁺ and ?^- at rest annihilate to produce two gamma rays that fly in the opposite directions. What is the wavelength of each gamma ray? The rest energy of a muon is 106 MeV and H = 6.63 × 10^-34 J·s.

The rest energy of W⁺ boson is about 80 GeV. What is the range of weak interaction? (h = 6.63 × 10^-34 J·s)

The reaction p + p ? p + ?⁺ + ? is allowed.

The reaction e⁺ + ?⁰ ? p + v_e is not allowed.

The K^- meson, with quark composition ${s }\overline{u}$ , has strangeness number S = +1.

The D⁺meson, with quark composition C = +1. $c \bar{d}$ , has charm number