A car company is performing brake tests on one of its cars. The car reaches a speed of 160 km/h and then hits the brakes to slow down at a rate of 11.0 m/s2 . A) How long does it take for the car to stop b) How far does the car travel when braking? A rate of 11.0 m/s2 .

a)  t = 4.04 s , b)  x = 89.77 m

Explanation:

This is a one-dimensional kinematics exercise.

a) Let's use caution to find the time, the vehicle speed when stopped is zero

         v = v₀ - at

let's reduce the magnitudes to the SI system

      v₀ = 160 km /h (1000m / 1km) (1h / 3600s) = 44.44 m / s

       0 = v₀ - at

        t = v₀ / a

        t = 44.44 / 11

        t = 4.04 s

b) to calculate the distance traveled we use

         x = v₀t - ½ a t²

         x = 44.44   4.04 - ½ 11.0 4.04²

          x = 179.54 - 89.77

         x = 89.77 m

it has to be b, about 97 percent.