Change of speed of a car turning in circles

AI Thread Summary
The discussion centers on the concept of friction and work in the context of a car turning in circles. While the textbook states that the friction force does no work, participants argue that without work, there can be no change in speed or kinetic energy. It is noted that a car can maintain a constant speed while turning, but to stop, a tangential friction component must act against the direction of motion. The conversation highlights the distinction between changing direction and changing speed, emphasizing that a car turning does not inherently stop unless an additional force is applied. Overall, the role of friction in both maintaining circular motion and facilitating deceleration is critically examined.
alingy1
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My textbook says : "The friction force on a car turning a corner does no work."

I agree somewhat. However, if there is no work, there is no change of speed, aka no change of kinetic energy.

How can a car in a real-life stop if it is doing perfect circles with forces pointing towards the center of those circles?

Is there another component of friction in play?
 
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I forgot to mention: I imply that the car driver is neither pushing the gas pedal nor the brakes!
 
alingy1 said:
My textbook says : "The friction force on a car turning a corner does no work."

I agree somewhat. However, if there is no work, there is no change of speed, aka no change of kinetic energy.

How can a car in a real-life stop if it is doing perfect circles with forces pointing towards the center of those circles?

Is there another component of friction in play?

Yes...There has to be a component of friction in tangential direction providing the required deceleration (i.e causing the speed to reduce ) .
 
alingy1 said:
My textbook says : "The friction force on a car turning a corner does no work."

I agree somewhat. However, if there is no work, there is no change of speed, aka no change of kinetic energy.

How can a car in a real-life stop if it is doing perfect circles with forces pointing towards the center of those circles?

Is there another component of friction in play?

The car does not stop when turning a corner - it moves along a circle.

Its velocity changes direction, but not magnitude. The speed stay constant.

When a car stops, some force is applied parallel to its velocity, opposite to it.

ehild
 
Tania beating me again:biggrin:

ehild
 
ehild said:
Tania beating me again:biggrin:

I saw you typing but didn’t notice you were replying to this thread :wink:
 

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