During the passage of 5 seconds, the vehicle’s speed decreased from 72 km / h to 36 km / h

During the passage of 5 seconds, the vehicle’s speed decreased from 72 km / h to 36 km / h. Determine vehicle acceleration during braking and braking distance?

To solve this problem, you first need to determine the difference between the initial and final vehicle speed.

To do this, we subtract 36 km / h from 72 km / h.

Will be:

V0 = 72 – 36 = 36 km / h.

We translate the found value of the speed into m / s.

Since in 1 km – 1000 meters, and in an hour – 3600 seconds, we get:

V0 = 36 * 1000/3600 = 36000/3600 = 10 m / s.

We find acceleration.

To do this, we divide the difference in speed by time.

a = 10/5 = 2 m / s2

Determine the braking distance.

S = V0 * t + (a * t2) / 2 = 10 * 5 + 2 * 25/2 = 50 + 25 = 75 meters.