# Question #6a426

Oct 22, 2017

Answer: $\Delta t = 3.9$ $\sec$

#### Explanation:

First, we can write out the given information:
${v}_{i} = 18.1$ $m \text{/} s$
$a = - 2.7$ $m \text{/} {s}^{2}$
${v}_{f} = 7.6$ $m \text{/} s$

Since we are looking for $\Delta t$, the change in time, we can use the equation:
${v}_{f} = {v}_{i} + a \Delta t$

Solving for $\Delta t$:
$a \Delta t = {v}_{f} - {v}_{i}$

$\Delta t = \frac{{v}_{f} - {v}_{i}}{a}$

Now we can substitute in our given values to find $\Delta t$:
$\Delta t = \frac{7.6 - 18.1}{- 2.7} = 3.89$ or $3.9$ $\sec$ to 2 significant figures.