4.5 Forces of Nature Flashcards
What are the four forces and interactions that occur between particles?
Strong force
Electromagnetic force
Weak nuclear force
Gravity
What is the force between the particle mediated (or transmitted) by?
Particles called bosons.
When does strong force occur?
In the nucleus between quarks and hadrons.
When does electromagnetic force occur?
With charged particles.
When does weak nuclear force occur?
Beta decay of nucleus.
When does gravitational force occur?
Due to mass.
What is the particle responsible for strong force?
Gluons (pions).
What is the particle responsible for electromagnetic force?
Photons- these have no mass and so leads to the force having an infinite range.
What is the particle responsible for weak nuclear force?
Bosons.
What is the particle responsible for gravitational force?
Gravitons?
What is the relative ranges for the forces?
Strong
Weak
Electromagnetic & Gravitational (infinite)
What is the relative strengths of the forces?
Strong
Electromagnetic
Weak
Gravitational
What carries the force between particles?
The bosons.
What fixes the range of the force?
The mass of the exchange particle.
Why is it the exchange particle cannot be detected during its transfer between the particles?
This would mean that it would no longer be acting as the mediator of the force between the particles.
The larger the rest mass of the exchange particle the…
Lower the time it can be in flight without it being detected and therefore the lower the range of the force.
The strong force is the strongest of the force, what does its strength enable it to do?
Overcome the large repulsive forces acting between the charged protons in the nucleus or between the quarks that make up the protons.
When is the strong force attractive?
At nuclear distances.
When is the strong force repulsive?
At very small distances.
What is the electromagnetic force?
The familiar force that we find exerted between charged particles at rest or in motion.
What happens in beta decay?
A neutron decays to a proton.
A W-boson is exchanged as a quark changes from down to up.
The W-boson then immediately decays into an electron and an electron anti-neutrino.
What does the fact that the W and Z particles responsible for weak interactions are very massive mean?
This leads to the force they give rise to being very short range, only about 0.01 of the diameter of a proton.
What interaction is the only way in which a quark can change into another quark, or a lepton into another lepton?
The weak interaction.
What is the weakest of the forces?
Gravitational force.
What is long range and the dominant force that operates within and between galaxies?
Gravitational force.
What is the electroweak force?
At high energies it has already been found that the electromagnetic force and the weak nuclear force cannot be distinguished. They merge to form one single force, the electroweak force.
Order of strength of the forces.
Strong force
Electromagnetic force
Weak nuclear force
Gravity
