TBR Physics Example 2.9b

[Sub Rosa]

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Question: Why does it become unsafe to take a turn in your car past a threshold speed?

Answer: The centripetal force can exceed the force holding your car to the road.

But the centripetal force pushes the car towards the center of the turn, so if it exceeded the force holding the car to the road, wouldn't the car collapse into the center of the circular path?

I don't understand why it's the centripetal force and not the centrifugal force that would exceed the force of friction between the car and road...

 

[sdm33]

Answer: The centripetal force can exceed the force holding your car to the road, what they trying to say that the tangential velocity can exceed the force holding your car to the road. The truth is that the tangential velocity is what causes you to fly out of the car for ever until another force stops you, it sounds scary. Now centrifugal force is not a force it is fake, and what is holding the car on the road it is not the force of friction , but the force of gravity pulling the weight of the car +passengers toward the center of the earth.

 

[Thoroughbred_Med]

I don't get sdm33's explanation. I'm at a loss for understanding this as well. Any help?

I though centripetal force points towards the center... and according to the equation (F=m*(v^2/r)), if velocity is increased shouldn't the Fc also increase???? thus, pulling the car towards the center as well, instead of having the car fly off the road as suggested in the question...

 

[DrknoSDN]

I don't get sdm33's explanation. I'm at a loss for understanding this as well. Any help?

I though centripetal force points towards the center... and according to the equation (F=m*(v^2/r)), if velocity is increased shouldn't the Fc also increase???? thus, pulling the car towards the center as well, instead of having the car fly off the road as suggested in the question...

He said it's not centripetal force but centrifugal force. For a comparison google: centripetal vs centrifugal force.

Centrifugal force is a concept and not a real force but uses the same equation as centripetal force. That's probably why the book used the word centripetal force while implying that inertia/momentum is a factor.