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

admin

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 kho:l, y ipxh7eoe67+ lu/ w, -kjk6naa 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 ,le z130.i6d gfq mnz; bq:wb.ztlw) jfundamental 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 examplen.z wi wtg:m)ebzb0f.q; 36, q 1llzjd: $$ P=F v $$ 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: $$ \mathrm{kg} \times \mathrm{ms}^{-2} \times \mathrm{ms}^{-1}=\mathrm{kg} \cdot \mathrm{m}^2 \cdot \mathrm{s}^{-3} . $$