An automobile traveling 50km/hr. it decelerates at 5 meter per second square. how long will it take to stop the car? how far will the car travel after a brakes are applied?

We know, a = v/t
Here, a = 5 m/s²
v = 50 km/h= 13.88 m/s

Substitute their values into the expression:
5 = 13.88 / t
t = 13.88/5
t = 2.78 sec

Now, we know, v = d/t
13.88 = d/2.78
d = 13.88 * 2.78
d = 38.53 meter

In short, Your Answers would be:
i) It will take 2.78 sec
ii) It will travel for 38.53 m after a brakes applied.

Hope this helps!