- #1
Jan Nebec
- 19
- 1
Hello!
I've been reading about relativistic mass for last few days and it leads me to even more confusion.
Supposing, we are assuming SR.
1. Why some people say that relativistic mass leads to confusion? As far as I learned, relativistic mass tells me the mass of an object, that is moving relative to me. So if I measure the mass of a moving electron, it would seem heavier, because I multiply it's rest mas with factor gama. I don't see any problems here?
2. Only problem that I see here is, that if someone uses relativistic mass instead of rest mass, he should carefully define velocity and frame of reference. Because for example, rest masses of 1kg and 10kg can both get relativistic mass of 100kg, so we have to define their velocity relative to observer to get full description.
3. However, relativistic mass can not be used to calculate gravitational attraction of an object! So it is useless in this respect. But I think it might be useful to describe it's inertial mass. But since we are told that inertial mass and gravitational mass are the same, I am confused, because increase of relativistic mass refers only to it's inertial mass. Am I right?
I've been reading about relativistic mass for last few days and it leads me to even more confusion.
Supposing, we are assuming SR.
1. Why some people say that relativistic mass leads to confusion? As far as I learned, relativistic mass tells me the mass of an object, that is moving relative to me. So if I measure the mass of a moving electron, it would seem heavier, because I multiply it's rest mas with factor gama. I don't see any problems here?
2. Only problem that I see here is, that if someone uses relativistic mass instead of rest mass, he should carefully define velocity and frame of reference. Because for example, rest masses of 1kg and 10kg can both get relativistic mass of 100kg, so we have to define their velocity relative to observer to get full description.
3. However, relativistic mass can not be used to calculate gravitational attraction of an object! So it is useless in this respect. But I think it might be useful to describe it's inertial mass. But since we are told that inertial mass and gravitational mass are the same, I am confused, because increase of relativistic mass refers only to it's inertial mass. Am I right?