A massless particle is a hypothetical particle that has no rest mass. This means that it travels at the speed of light and has no internal structure or physical dimensions.
Since massless particles have no rest mass, they cannot interact with forces that require mass, such as gravitational forces. However, they can still be affected by other forces, such as electromagnetic forces or strong and weak nuclear forces.
Yes, even though they have no rest mass, massless particles can still have momentum. This is because momentum is defined as the product of mass and velocity, so even if the mass is zero, the particle can still have momentum if it is moving at the speed of light.
Yes, massless particles still obey Newton's laws of motion. However, since they have no mass, the equations may look different or may not apply in certain situations. For example, for a massless particle, the equation F=ma would become F=0, since the mass is zero.
The most well-known example of a massless particle is the photon, which is the particle of light. Other examples include gluons, gravitons, and some theoretical particles such as the Higgs boson. These particles are all fundamental particles that have no rest mass.