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I read in a book that mass is invariant. Does this mean that an object's mass does not increase as it approaches the speed of light?
If an object starts moving relative to you then its mass would be larger compared to when it was at rest relative to you. What is invariant is rest mass i,e the mass of any object when it is at rest relative to you.I read in a book that mass is invariant. Does this mean that an object's mass does not increase as it approaches the speed of light?
In most modern treatments, that's the case. What increases is the object's energy. In the past this was called "relativistic mass", but since we already have a perfectly good word to describe it, this terminology has fallen out of favor.I read in a book that mass is invariant. Does this mean that an object's mass does not increase as it approaches the speed of light?