Physics Help Forum Should the word "relative" be used when discussing kinetic energy of Systems?

 Oct 5th 2016, 04:32 AM #2 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,347 KE is calculated from $\displaystyle KE=\frac 1 2 m v^2$ , and velocity is measured relative to the observer. So yes - the calculation of KE is relative to the observer. For that matter we know from Einstein's Theory of Relativity 'm' is also relative. Hence an object's KE is not absolute. topsquark likes this. Last edited by ChipB; Oct 5th 2016 at 04:37 AM.