Space Time & Motion A.1 Kinematics (id: ceab64951)

本题目来源于试卷: Space Time & Motion A.1 Kinematics，类别为 IB物理学

[单选题]
The diagram below shows a ca5l6ransr ji//r of mass m descending a slope. The car, initial; z+vm t*s8ftkly at rest, coverf t*;+8mtvzs ks a distance of $27\,m$ in $3.0\,s$

The magnitude of the acceleration is given by

A. $3.0\,m\,s^{-2}$
B. $6.0\,m\,s^{-2}$
C. $9.0\,m\,s^{-2}$
D. $81\,m\,s^{-2}$


参考答案:  B


本题详细解析:
From the equation of motion $s = ut + \frac{1}{2}at^{2}$, initially the velocity, $u$ is zero. $\Rightarrow a = \frac{2s}{t^{2}}$ Substituting $t = 2s$ $\frac{(2)(27.0 \text{ m})}{3^{2}} = 6.0 \text{ m s}^{-2}$

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