Kognity IB Physics A.0 Measurements & Uncertainty (id: 4a1233956)

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本题目来源于试卷: Kognity IB Physics A.0 Measurements & Uncertainty，类别为 IBDP Physics

[单选题]
Which of the followi,0(*tm cr) 3cf ksamp;lrl.l mi0 mk8 fftj9*+lh0houng could be a unit of power?

A. $kg \cdot m \cdot s^{-2}$
B. $kg \cdot m^2 \cdot s^{-1}$
C. $kg \cdot m^2 \cdot s^{-2}$
D. $kg \cdot m^2 \cdot s^{-3}$


参考答案:  D


本题详细解析:
All derived units can be written in terms of fundamental un/f5i d6 slhz jhgf)pq 35lj,o/its by considering the equations you would use to calculate the derived value. By replacing eachh/gs/l h d65 fq 5o,zpif)lj3j term with its unit in the equation, you can obtain the new unit. For example: $$ P=F v $$ where $P$ is power, $F$ is force and $v$ is velocity. In turn: $$ F=m a $$ where $m$ is mass and $a$ is acceleration. So we could write: $$ P=m a \times v $$ and the unit of power in terms of fundamental units must then be: $$ \mathrm{kg} \times \mathrm{ms}^{-2} \times \mathrm{ms}^{-1}=\mathrm{kg} \cdot \mathrm{m}^2 \cdot \mathrm{s}^{-3} . $$

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