# What is an object's acceleration if it is moving at 30 m/s and comes to a stop in 5 s?

Oct 25, 2016

The object's acceleration is $\text{-6 m/s"^2}$.

#### Explanation:

Remember:
a = (∆v)/(∆t)
and

∆v = v_f - v_i

So, in this case:
${v}_{i} = \text{30 m/s}$ [fwd]
${v}_{f} = \text{0 m/s}$ (it comes to a stop)
∆t = 5s

Thus,
a = (∆v)/(∆t)

a = (v_f - v_i)/(∆t)

$a = \frac{- 30 \frac{m}{s}}{\text{5s}}$

$a = \text{-6 m/s/s" or "-6 m/s"^2}$