Accelerated Motion and Gravity Equivalence

It seems a principal of Einstein’s General Theory of Relativity that there is an equivalence between accelerated motion and being in a gravitational field.  It seems that an observer would have no way to tell the difference between these two states.  However, the gravitational force being mediated by elementary force carrying particles (gluons I think), [...]

How to describe momentum physically ?

Kiran asks: “How do you describe momentum physically by not in definitions like product of mass and velocity?” Answer: Momentum is defined as “Mass in Motion” or “The quantity of motion“. Momentum is a measure of the “effect” a moving body can produce. It is a measure of the “effort” required to bring a body to [...]