2.1.4: Power
- Page ID
- 84574
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If energy is transferred from one object to another (e.g., for performing work), it is not only important to know how much energy is passed, but it may also be essential to know how fast this energy is delivered. So, there is a special unit describing the rate of energy transfer, called Watt. Its symbol is "W", and it's defined as the transfer of one Joule per one second:
\[
1 \mathrm{~W}=\frac{1 \mathrm{~J}}{1 \mathrm{~s}}=1 \frac{\mathrm{kg} \cdot \mathrm{m}^{2}}{\mathrm{~s}^{3}}
\]