Recent content by Jan Nebec

Great thanks for this video! It's a really good one :)

The Special Theory of Relativity is based on two principles. The first one is, that if you have two objects, then it is not possible to tell which object is moving, and which object is standing still. So someone moving in a spaceship relative to observer, can't say who is actually moving and who...

Thank you! I think I've got what I needed :)

Huh...this thread became one big mess and I am even more confused...so is there any general proof that inertial mass doesn't increase with velocity? Asumming only SR.

Velocity addition only tells me that relative velocity between objects can never exceed the speed of light. But it doesn't quite explain why objects resist acceleration more and more when they gain speed?

Well yes, the exact formula can be found here: https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcRqjY5gTfYw8diKXFmta07ozKASLLhZFQPugMPPkr01AntmQ_tU

Well...what I'm saying is, that it is a fact that an object with a velocity approaching ##c## will seem harder and harder to accelerate because of the increase of it's inertial mass? And this is a mass calculated with multiplying the rest mass with ##\gamma## or ##\gamma^3##, depens of the...

Yes, I was referring to that part of an article. But I needed more specific mathematical proof for such statement, since in high schools they don't teach acceleration from such deep approach.

No, I understand that SR doesn't include gravity and that mass multiplied with gamma factor must not be used to calculate gravitational attraction of an object. If I stay only in SR, can I say that relativistic mass is equal to inertial mass but gravitational mass stays same as rest mass?

Okay, so for now, just for a concept, can I have an explanation that only inertial mass (that is equal to this confusing relativistic mass) increases with velocity, because an object is harder and harder to accelerate when it approaches the speed of light?

Great thanks for this explanation! It's so nice to see how people here are helping others!

Hello! Why does resistance to acceleration depend on both the velocity of the object as well as the direction of the force? In circular motion, we can measure the centripetal force and centripetal acceleration, then we can calculate objects mass. Speed remains constant. But we would get the...

Thank you very much! I think it's the best answer I could get so far! How to prove, that calculated "mass" = ##\gamma{m_0}## if the applied force is perpendicular to the direction of motion? And how to prove the correlation when direction of the force is same as it's velocity vector?

1. Well yes, I thought relativistic mass of that object moving relative to me. 2. Why if speed is constant? It would also work if an object accelerates. The object would seem harder and harder to accelerate, due to increase of relativistic mass. 3. How is it called then?

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...