esha said:
The cannot stop immediately, so you need slippage somewhere: at the brakes or at the tire. Which of them will slip depends on the ratios of friction and radii.esha said:
You have chosen a particularly confusing scenario here, I think. You have your foot down hard on the accelerator and the wheels would spin but you apply the brakes to stop it happening. What is happening is that you are applying a force (a torque, actually) with the (internal) brakes in the opposite direction which results in a lower torque being applied the wheels - so less force between tyre and road. Forces and torques add up vectorially so one torque can subtract from another.esha said:
esha said:
but my point is that if the brakes are applied to reduce the net force on the car then how will it suddenly exceed the force applied by static friction if earlier the case want so ??CWatters said:
When brakes are applied at constant speed speed, the magnitude of the net force increases.esha said:
What does Newton's First Law tell you?esha said:
The brakes are applied to increase the force on the car. The harder you press the more braking force there is up to the limit due to static friction.esha said:
The brakes try and make the wheel skid, increasing the friction force between wheel and road.esha said:
How would the car brake, without a net force on it?esha said:
It does.esha said:
Indeed it does. It's just that most cars can't accelerate fast enough to reach that point (on a dry road), but they can brake hard enough.esha said:
esha said:
No. In order to stop the acceleration, you just lift your foot off the gas pedal, which stops the engine from producing a driving torque. This scenario has nothing to do with stopping the car; it only results in the car coasting.esha said:
Since the scenario you presented has nothing to do with stopping a car, this doesn't either: f=ma, sure, but it isn't the engine torque you are opposing when stopping the car, it is the inertia of the car. So you can apply whatever force you want to achieve whatever deceleration you want (or vice versa) up to the point where the friction on the tires can no longer apply that force.
You seem to be missing Newton's first law: when the car is in motion at constant speed, the net force is zero. So that isn't why the brakes are applied. The brakes are applied to create a net force on the car.esha said:
Because they are totally unrelated.
I'm sorry, but this doesn't look quite correct to me.CWatters said:
When brakes are applied too hard, the wheels of the car can lock up and lose traction on the road. This causes the car to skid because the tires are unable to grip the road surface and the car continues to move forward due to the momentum.
The wheels lock up when the brake pressure is too high, which causes the brakes to engage too forcefully and overpower the friction between the tires and the road. This can also happen if the brake pads are worn or if there is a malfunction in the brake system.
Skidding can be dangerous because it reduces the driver's control over the vehicle, making it difficult to steer or stop. In addition, skidding can cause the car to lose balance and potentially spin out of control, leading to accidents.
Skidding can be prevented by applying the brakes gently and gradually, rather than slamming on them. This gives the tires time to maintain traction with the road and allows the driver to maintain control of the vehicle. It is also important to regularly check and maintain the brake system to ensure it is functioning properly.
If your car starts to skid, remain calm and do not panic. Take your foot off the brake and steer in the direction you want the car to go. Avoid overcorrecting or jerking the steering wheel, as this can make the skid worse. Once the car regains traction, gently apply the brakes to slow down and regain control.