Forces

• The fundamental forces: Gravity, Coulomb (electrostatic), Strong nuclear, weak
• Force can be defined as: something that effects and changes the momentum of a particle and the unit to measure force is newtons (N)

How can forces act at a distance?

• Transient (impermanent) particles pass between particles
• These are called exchange particles

• Force: Electromagnetic
• Exchange Particle: Virtual Photon
• Symbol(s): Y
• Range: Infinite

• Force: Gravity
• Exchange Particle: Graviton
• Symbol(s): Theoretical
• Range: Infinite

• Force: Weak
• Exchange Particle: W Bosons
• Symbol(s): W+, W-
• Range: Short (approx. 0.001fm)

• Force: Strong
• Exchange Particle: Gluon
• Symbol(s): g
• Range: Short (<3 fm)