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course_planning:course_notes:momentum [2014/07/08 12:16] – created caballero | course_planning:course_notes:momentum [2014/07/08 12:31] (current) – [Momentum] caballero | ||
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===== Momentum ===== | ===== Momentum ===== | ||
- | A [[course_planning: | + | A [[course_planning: |
==== Changes in Motion ==== | ==== Changes in Motion ==== | ||
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where the proportionality constant is needed when [[http:// | where the proportionality constant is needed when [[http:// | ||
- | $$\gamma = \dfrac{1}{\sqrt(1-\left(\dfrac{|\vec{v}|}{c}\right)^2}$$ | + | $$\gamma = \dfrac{1}{\sqrt{1-\left(\dfrac{|\vec{v}|}{c}\right)^2}}$$ |
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+ | ==== When does the γ factor matter? ==== | ||
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+ | For most motion that is fair from the speed of light, the γ factor will not matter so much. For example, consider the following table of speeds. | ||
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+ | ^ |→v| m/s ^ |→v|/c | ||
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+ | | 2.9997e8 | ||
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+ | For most purposes, γ≈1, so we can often use the approximate formula for the momentum vector, | ||
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+ | $$\vec{p} = m\vec{v}$$ |