# Question #df506

Jun 13, 2015

THe answer is b) ${\text{3.2 m/s}}^{2}$.

#### Explanation:

So, you know the distance the trolley covers and the time it needs to do so. Another important piece of information you have is the fact that its initial velocity is zero.

The equation that establishes a relationship between distance and time looks like this

$d = {\underbrace{{v}_{0}}}_{\textcolor{b l u e}{\text{=0}}} \cdot t + \frac{1}{2} a {t}^{2}$

In your case, the equation will be

$d = \frac{1}{2} a {t}^{2}$

Plug your values into this equation and solve for $a$ to get

$1.6 {\text{ m" = 1/2 * a * ("1 s")^2 = 1/2a " s}}^{2}$

$a = \left(1.6 \cdot 2 {\text{ m")/("s"^2) = color(green)("3.2 m/s}}^{2}\right)$