Final answer:
To stop a car without antilock brakes quickly on icy roads, the best method is to pump the brakes gently, using a technique known as threshold braking to avoid wheel lock-up and maintain control. Slamming on the brakes could lead to a loss of steering control due to wheels skidding.
Step-by-step explanation:
If you want to stop a car without antilock brakes as quickly as possible on an icy road, the best method is to pump the brakes gently. This technique, known as threshold braking, involves applying the brakes to the point just before the wheels lock, and then releasing the pressure slightly, repeatedly. It helps maintain traction and control, which is essential because ice significantly reduces the friction between the tires and the road surface.
The reality of the situation is that without antilock brakes, slamming on the brakes could cause the wheels to lock up, leading to a loss of steering control. By pumping the brakes, you mimic what an antilock brake system (ABS) would do: alternating between applying and releasing brake pressure to maximize the amount of kinetic friction without causing the wheels to skid. Good static friction is desirable; it's the friction that exists between two objects that are not moving relative to each other, which means more control of your vehicle.
As for why more friction is sometimes desirable, during wintertime, drivers often switch to winter tires because they are designed to create more friction on icy and snowy roads, aiding in better traction and control.