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 car of mass 7,.zxs0b xbyym descending a sl m )m 1+etsrbx8ope. The car, initially at rest bsem )m1xrt8+, covers 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 $t = 2s$ $\frac{(2)(27.0 \text{ m})}{3^{2}} = 6.0 \text{ m s}^{-2}$
| 
