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 un lh7)7m/ - vugz9ucvf :vg iae6(.gebxit of por5zhz6a tq )a 15l/jg3uygig:wer?
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 tekesa x1i5)ja eq sd;7j3m+r*erms of fundamental units by considering the equations you would use to cae7k)3e*aqss i15 ;ja+r dxemjlculate the derived value.
By replacing each 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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Post time 2024-8-21 21:17:15