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## Main Question or Discussion Point

My textbook explains relativity with the help of relativistic mass...

My questions are-

1. Does relativistic mass has any effect in gravity? I mean do the object with more velocity attract things stronger than before?

2. I will see the object which going at a high velocity (from my reference frame) with a contracted length and its time dilated... I understand that(well after having the shock)... But I don't understand how its mass gets increased? Well energy and mass are equivalence and it has got extra kinetic energy... But If we say extra mass that would mean extra gravity... Well if you answer my 1st question this question will be answered too...

3. Two objects with invariant mass m1 and m2 collide and become one... Their relativistic mass was M1+M2... Now what would be their invariant mass? m1+m2? or M1+M2... Isn't it m1+m2... Then why we use the term 'relativistic mass'?

Another thing... Newton said F = d(mv)/dt

now we say m is the mass(relativistic)... But as he is dead long ago(with his mistakes which are apparently true at low velocities :tongue2: ) then would it be wrong to say that this is true if we divide the mass(invariant) by a gamma factor...

My questions are-

1. Does relativistic mass has any effect in gravity? I mean do the object with more velocity attract things stronger than before?

2. I will see the object which going at a high velocity (from my reference frame) with a contracted length and its time dilated... I understand that(well after having the shock)... But I don't understand how its mass gets increased? Well energy and mass are equivalence and it has got extra kinetic energy... But If we say extra mass that would mean extra gravity... Well if you answer my 1st question this question will be answered too...

3. Two objects with invariant mass m1 and m2 collide and become one... Their relativistic mass was M1+M2... Now what would be their invariant mass? m1+m2? or M1+M2... Isn't it m1+m2... Then why we use the term 'relativistic mass'?

Another thing... Newton said F = d(mv)/dt

now we say m is the mass(relativistic)... But as he is dead long ago(with his mistakes which are apparently true at low velocities :tongue2: ) then would it be wrong to say that this is true if we divide the mass(invariant) by a gamma factor...