A car is gong at a speed of 21.6 km/hr when it encounters a 12.8 m slope of angle 30 degree .The friction coefficient b/w road & tyre is 1/(23).Show dat no matter how hard the driver applies the brakes ,the car will reach the bottom with a speed greater than 36 km /hr.Take g=10m/s²

The fig is:

 

My doubt is:

1.Which friction will act b/w tyre & road (kinetic or static)

2. How did the brakes act in a car. That by applying brakes we stop the rotation motion of the tyre or the slipping of the tyre on the roads

Plz give me the complete & best solution with all the technical possibiliies of this ques

i wud be highly obliged for it

Thanx