What is about mess and velocity, and how to measure it?

Question

When speed is bigger, mass is bigger.
But speed is bigger than what? And when we measere mass in two different speed, we get two different mass? And how to measer speed at two different speed? So is mass the property of the thing AND the measurer? (Than I'm only 77 kilos:))

I don't mean impulse, but mass.
The great question is mass belongs to the thing, or to the thing and the watcher, not the force it can make.

Answer 1

Mass is a property of matter. It is a measure of its resistance to an external force trying to change its velocity. Thus Newtons first and second laws. Mass was considered to be constant, for a long time, but it was found that that is not the case. For instance if the velocity of an object increase 2 times, the Kinetic Energy would increase 4 times and viceversa. But it was found that when the kinetic energy of electrons traveling at speeds close to that of light was quadrupled, the velocity was not doubled as would be expected. This lead scientists to the conclusion that mass is not constant but increases with the velocity. This is perceptible at speeds close to that of light.

Answer 2

No the mass stays the same as speed gets bigger, however, the velocity changes therefore the mass impact changes. Example 100 lbs at 1 mph force is 100 lbs, at 2 mph the force doubles to 200 lbs. etc. This of course if nothing else changes. You cannot measure speed at two different speeds, but you can measure force. I think this is what you are after.

Answer 3

when you travel at a speed very close to that of light your mass increases rapidly and it tends to infinity. the relation between speed(v) and mass(M) is

M= m*c /(sqrt( c*c - v*v ))
where c is the speed of light and m is mass of the object at rest