When the car is parked, the force of static friction is greater than the force of gravity pulling the car down the hill. This is because the weight of the car is distributed evenly over all four tires, which increases the contact area between the tires and the road. The greater the contact area, the greater the force of static friction.
The force of static friction is also affected by the coefficient of static friction between the tires and the road surface. The coefficient of static friction is a measure of how much friction there is between two surfaces when they are in contact. The higher the coefficient of static friction, the greater the force of static friction.
In the case of a car parked on a hill, the coefficient of static friction between the tires and the road surface is typically high, which helps to keep the car stationary. However, if the road surface is wet or icy, the coefficient of static friction will be reduced, which could cause the car to slide down the hill.
To prevent your car from sliding down a hill when parked, you should always set the parking brake and put the car in gear. The parking brake will help to hold the car in place by applying the brakes on the rear wheels, while putting the car in gear will help to prevent the car from rolling forward or backward.
