I remember my teacher saying that anti-lock brakes worked better

[cragar]

I remember my teacher saying that anti-lock brakes worked better because of the static friction coeffiecient was higher than the kinetic friction, but i never understood why. Is it beacuse when you stab the brakes their is a larger impulse?

 

[russ_watters]

The static friction coefficient between the wheels and the ground is higher than the kinetic friction coefficient. It doesn't have anything to do with how hard you push on the pedals - it is typical of most static and kinetic friction situations.

 

[hellboy4444]

carry out a simple experiment:
take an object ,keep it on a flat surface. Now start tilting the table SLOWLY. not down the angle with horizontal the surface makes at which the object just starts sliding. the this is alpha.
Now take a vibrating surface which continuously vibrates with a small amplitude. The vibration shall be in the horizontal direction and sufficiently rapid. Keep the object on it. tilt the surface. Note the angle again, say, beta.
compare alpha and beta.
you will find that alpha>beta. Why?
this is because coeff. of friction in static condition is more than than in dynamic condition.

 

[cragar]

thanks for the responses guys, so when I raise the plane and its vibrating the object will slide sooner.

 

[PJC01]

Your teacher was correct in saying that anti-lock brakes work better due to the difference in static and kinetic friction coefficients. When a car's brakes are applied, the tires experience a force of friction against the road surface. This friction force helps to slow down the car. However, the friction force is dependent on the type of friction present between the tire and the road surface.

Static friction occurs when two surfaces are in contact but not moving relative to each other. In the case of a car's tires, this would be when the car is stationary or when the brakes are first applied. Kinetic friction, on the other hand, occurs when two surfaces are in motion relative to each other. This would be when the car is moving and the brakes are being applied.

The static friction coefficient between the tire and the road surface is typically higher than the kinetic friction coefficient. This means that when the brakes are first applied, the static friction force is greater than the kinetic friction force. This allows for a larger impulse, or change in momentum, to be applied to the car, resulting in a quicker and more efficient stop.

In contrast, if the brakes were continuously applied, the kinetic friction force would eventually become greater than the static friction force. This would result in a decrease in the impulse applied to the car and potentially longer stopping distances.

In summary, the difference in static and kinetic friction coefficients allows for anti-lock brakes to work better by providing a larger initial impulse and maintaining a consistent level of friction force between the tires and the road surface.