On a horizontal section of the road, a car with a mass of m = 1700 kg, moving at a speed of 36 km / h

On a horizontal section of the road, a car with a mass of m = 1700 kg, moving at a speed of 36 km / h, brakes in front of a traffic light. Find the path S to stop, the braking time t, the vehicle’s acceleration during braking and its initial kinetic energy. The coefficient of friction during braking is = 0.4.

Ek – kinetic energy, Atr – friction work, n – friction coefficient
Eк = (mv ^ 2) / 2
Ek = 85 kJ

For ZSE:
Ek-Atr = 0
Attr = Ftr * S = (mgn) S

S = 12.5 m

a = v ^ 2 / 2S
a = 4 m / s. ^ 2 (considering the direction a = -4 m / s. ^ 2)

S = vt- (at ^ 2) / 2
t = 2.5 s.