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/(lpn -od 0*kxb-zncjv.xkhe5iz/ s* ng 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 fundamentalz(v:8/ h9v.ym4. 2vzt wjx/s wglbmrx units by considering the equations you would use to calculate the derived value. By replacing each term with its unit in the equation, you can obtain the new unit. For e: vxz r./s4mvh.twzj(xl9/8g vmy2wb xample: $$ P=F v $$ 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: $$ \mathrm{kg} \times \mathrm{ms}^{-2} \times \mathrm{ms}^{-1}=\mathrm{kg} \cdot \mathrm{m}^2 \cdot \mathrm{s}^{-3} . $$