A car moving at a speed of 36 km / h stops when braking for 2 seconds, what is the acceleration of a car.

First, we need to translate the speed into SI: 36 km / year = 36 × 1000 m / 3600 s = 10 m / s.

Now we know that the initial speed is 10m / s and the final speed is 0 and knowing the acceleration formula: a = (v (final) -v (initial)) / t

We have all the quantities so we define the acceleration:

a = (0-10) / 2 = -5 (m / s ^ 2) (negative number because it slows down)

Answer: -5m / s ^ 2.