# Worksheet: Identifying Particles in Detectors

In this worksheet, we will practice determining the charge and mass of particles from the paths that they follow through particle detectors.

Q1:

An up quark has a mass of 2,300 keV/c2. What is the mass of an up quark in kilograms? Give your answer to 3 significant figures.

• A kg
• B kg
• C kg
• D kg
• E kg

Q2:

What is kg in mega-electron volts per speed of light squared (MeV/c2)? Give your answer to 3 significant figures.

Q3:

An electron has a mass of kg. What is the mass of an electron in kilo-electron volts per speed of light squared (keV/c2)? Give your answer to 3 significant figures.

Q4:

A muon has a mass of 106 MeV/c2. What is the minimum energy of a photon that can produce a muon and an antimuon via pair production? Give your answer in mega-electron volts.

Q5:

A tauon has a mass of 1,780 MeV/c2 and a muon has a mass of 106 MeV/c2. What is the ratio of the mass of a tauon to the mass of a muon? Give your answer to 3 significant figures.

Q6:

An electron has a mass of 511 keV/c2. What would the energy of a photon that was produced from the annihilation of an electron and a positron be? Assume that the kinetic energy of the two particles is negligible. Give your answer in kilo-electron volts.

Q7:

What is 15.0 eV/c2 in kilograms? Give your answer to 3 significant figures.

• A kg
• B kg
• C kg
• D kg
• E kg

Q8:

A muon moves through a uniform magnetic field with a field strength of 0.100 T. It has a constant speed of m/s. What is the radius of the circular path that it follows? Take the muon to have a mass of kg and a charge of C. Give your answer to 3 significant figures.

Q9:

What magnetic field strength of a uniform magnetic field is required to make an electron moving at a speed of m/s follow a circular path with a radius of 10.0 cm? An electron has a charge of C and a mass of kg. Give your answer in teslas to 3 significant figures.

• A T
• B T
• C T
• D T
• E117 T

Q10:

A charged particle moves through a uniform magnetic field in a bubble chamber. It moves along a circular path with a radius of 10.0 cm. Its speed is m/s and its mass is kg. The strength of the magnetic field is 0.280 T. What is the charge of the particle? Give your answer in coulombs to 3 significant figures.

• A C
• B C
• C C
• D C
• E C

Q11:

The diagram shows a charged particle moving through a uniform magnetic field. The particle moves along a circular path. Which of , , , and shows the direction of the force experienced by the charged particle due to the magnetic field? • A
• B
• C
• D

Q12:

A charged particle moves through a uniform magnetic field in a bubble chamber. It moves along a circular path with a radius of 4.44 mm. Its speed is m/s and its charge is C. The strength of the magnetic field is 0.210 T. What is the mass of the particle? Give your answer in kilograms to 3 significant figures.

• A kg
• B kg
• C kg
• D kg
• E kg

Q13:

A charged particle moves through a uniform magnetic field. It moves along a circular path with a radius of 0.0200 m. Its speed is m/s. The strength of the magnetic field is 0.200 T. What is the charge to mass ratio of the particle? Give your answer in C/kg to 3 significant figures.

• A C/kg
• B C/kg
• C C/kg
• D C/kg
• E C/kg

Q14:

A particle with a mass of is observed in a bubble chamber. The magnetic field inside the bubble chamber is uniform and has a strength of 0.340 T. The particle moves along a circular path with a radius of 31.3 cm at a speed of m/s. What is the magnitude of the relative charge of the particle?

Q15:

The diagram shows a charged particle moving through a uniform magnetic field. The particle moves along a circular path. Which of , , , and shows the direction of the instantaneous velocity of the charged particle?

• A
• B
• C
• D

Q16:

A particle moves through a uniform magnetic field of strength 0.15 T. The particle moves in a straight line at a speed of 250 km/s. What is the relative charge of the particle?

Q17:

Which of the following is the correct formula for the force experienced by a particle with electric charge moving through a uniform magnetic field of strength at a speed ?

• A
• B
• C
• D
• E

Q18:

A charged particle moving in a magnetic field experiences a force in a direction the direction of the instantaneous velocity of the particle.

• Aparallel to
• Bequal to
• Cperpendicular to
• Din the opposite direction to

Q19:

What is kg in ? Give your answer to 3 significant figures.

Q20:

A charged particle passes through a uniform magnetic field in a bubble chamber. It decays to particle , which is also a charged particle, and a number of neutral particles, which cannot be seen in the bubble chamber.

If particle initially has the same speed as particle , which particle has the greatest charge-to-mass ratio? • A
• B

Q21:

The diagram shows the paths of two particles in a uniform magnetic field in a bubble chamber. Both particles have the same initial velocity. If particle P is an electron, what is particle R?

• AA muon
• BA neutron
• CA positron
• DA photon
• EA meson

Q22:

The diagram shows the paths of two particles in a uniform magnetic field in a bubble chamber. Both particles have the same mass and initial velocity. If particle has an electric charge of , what is the electric charge of particle ? • A0
• B
• C
• D
• E

Q23:

The diagram shows the paths of two particles in a uniform magnetic field in a bubble chamber. Particle has a charge of and particle has a charge of . Both particles have the same initial speed. Which particle has the greater mass?

• ABoth have equal masses.
• B
• C

Q24:

The table shows the charge-to-mass ratio of three mesons.

 Particle Charge-to-Mass Ratio (C/kg) 𝜋 Κ 𝐷 6.43×10 1.82×10 4.80×10

A particle moves through a uniform magnetic field of strength 0.01 T along a circular path with a radius of 0.625 m at a speed of 300 km/s. Which of the particles listed in the table could be that particle?

• A
• B
• C

Q25:

A pion is observed in a bubble chamber. The magnetic field inside the bubble chamber is uniform and has a strength of 0.330 T. The pion moves along a circular path with a radius of 1.98 cm at a speed of m/s. What is the mass of the pion? A pion has a relative electric charge of . Give your answer in mega-electron volts per speed of light squared to 3 significant figures.