Step-by-step explanation:
The car is going at 60 m/s (and not whatever unit you were using).
Which means - it travels 60 meters (or roughly 200 ft) per second.
And it decelerates at 10 m/s2, or more precisely, at 10 m/s^2 .
What is this? It changes the speed by 10 meters per second —- each second.
So it is 10 meters by second … squared.
So how long will it take to get from 60 m/s to a standstill, if it can change (reduce) the speed by 10 m/s - each second? You have guessed it - it will be 6 seconds.
Now let’s put this into the terminology of physics:
If t means time, v is velocity and a stands for acceleration, the formula is
v = a . t
t = v / a
t = 60 m/s / 10 m/s2 = 6 s
Now it gets a bit tricky. How long will the braking distance going to be?
Well, at the beginning it will be fast, but at the end it will be slow.
On average, it will travel the same distance as going half the speed for the full time.
s stands for distance, so it will be
s = v / 2 . t
s = 60 m/s / 2 . 6 s = 30 m/s . 6 s = 180 m.
Just don’t mix up s as the symbol for distance and s as the unit for time (second).
And this is it.
In reality a race car can decelerate at high speed stronger since it has down force which allows the tires to have a stronger grip, this is far beyond the exercise in physics you have here.
