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 following could be a uvldwm(nw0n8s4 f a8 x+nit of powehq:f.qt fnw,s(* l8iqp fg.bavhz9 6 8r?

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 unitsx 2h8vac9c)hc by considering the equations you would use to calculate the derived value. By replacing each term with its8cc c9xa2hh )v 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: $$ \mathrm{kg} \times \mathrm{ms}^{-2} \times \mathrm{ms}^{-1}=\mathrm{kg} \cdot \mathrm{m}^2 \cdot \mathrm{s}^{-3} . $$