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 unit;v8 ymd62 l0v4hiteh5e wcou. of* 7cbq bk1rd.1nakcs1 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 mrtb89, pthk 54yxsd-( exi5azs* u3swritten in terms of fundamental 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 ne9i *aux4s 35b- xhmy 5rp (et8zks,dtsw 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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