3.2.1.4 - Particle Interactions

Question 1

What are used to measure force?

Answer 1

Newtonmeters and force sensors.

Question 2

When happens when a single force acts on an object?

Answer 2

It changes the momentum of the object.

Question 3

What is electromagnetic repulsion between?

Answer 3

Two of the same particles.

Question 4

What is electromagnetic repulsion due to?

Answer 4

Virtual photons.

Question 5

What does the weak interaction cause a neutron to do|?

Answer 5

Change into a proton in beta decay.

Question 6

What is the equation for beta- decay?

Answer 6

neutron -> proton + electron + electron anti-neutrino.

Question 7

What happens during beta+ decay?

Answer 7

Proton changes into a neutron.

Question 8

What is the equation for beta+ decay?

Answer 8

proton -> neutron + positron + electron neutrino

Question 9

Differences between W bosons and photons?

Answer 9

• W bosons have a rest mass of not 0. Therefore they have mass unlike photons.
• W bosons carry a charge. The photon is uncharged.
• W bosons have a very short range, 0.001fm.

Question 10

What does the W- boson do?

Answer 10

Decays into a beta- and an antineutrino.

Question 11

What does the W+ boson do?

Answer 11

Decays into a beta+ and a neutrino.

Question 12

What else gives rise to beta decay?

Answer 12

Interactions with neutrinos and antineutrinos.

Question 13

What is the equation for the interaction between W+ bosons?

Answer 13

proton + antineutrino -> neutron + positron

Question 14

What is the equation for the interaction between W- bosons?

Answer 14

neutron + neutrino -> proton + electron

Question 15

What is electron capture?

Answer 15

When a proton turns into a neutron through the interaction with an inner shell electron.

Question 16

What is electron capture mediated by?

Answer 16

The weak interaction.

Question 17

What is the equation for electron capture?

Answer 17

proton + electron -> neutron + neutrino (W+)

Question 18

What is an electron-proton collision mediated by?

Answer 18

W+

Question 19

What are photons and W bosons and why?

Answer 19

Force carriers because they are exchanged when the electromagnetic force and the weak nuclear force act respectively.

Question 20

What are gauge bosons?

Answer 20

Virtual particles which only exist for a very short time.

Question 21

1ev =

Answer 21

1.6 x 10^-19J

Question 22

What causes extra particles to be created when two particles collide?

Answer 22

Energy and mass are equivalent. When two particles collide, there is a lot of energy at the point of impact. This energy is converted to mass.