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The term "rest mass" + kinetic energy comes from the need to take account of the effects of [[special relativity]] on the apparent (or "observed") mass of an electron. It is impossible to "weigh" a stationary electron, and so all practical measurements must be carried out on moving electrons. However special relativity shows that the mass of an object appears to increase as its speed ''v'' (relative to the |
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The term "rest mass" + kinetic energy comes from the need to take account of the effects of [[special relativity]] on the apparent (or "observed") mass of an electron. It is impossible to "weigh" a stationary electron, and so all practical measurements must be carried out on moving electrons. However special relativity shows that the mass of an object appears to increase as its speed ''v'' (relative to the UNIFINISHED!!!! 8=D |