BR CBT friction question

[Ghayoour]

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Which of the following reasons explains why a skidding car takes longer to stop than one that is not skidding?

A. A skidding tire transfers momentum more effectively than a rolling tire
B. The coefficient of static friction between the car’s tires and the road surface is greater than the coefficient of kinetic friction
C. The skidding car loses some of the mass of its tires on the road surface
D. The force of kinetic friction is greater than the force of static friction between the car’s tires and the road surface

The answer is B can someone give me a better explanation as to why? I know its A or C for sure.

 

[WhiteWashed]

Which of the following reasons explains why a skidding car takes longer to stop than one that is not skidding?

A. A skidding tire transfers momentum more effectively than a rolling tire
B. The coefficient of static friction between the car’s tires and the road surface is greater than the coefficient of kinetic friction
C. The skidding car loses some of the mass of its tires on the road surface
D. The force of kinetic friction is greater than the force of static friction between the car’s tires and the road surface

The answer is B can someone give me a better explanation as to why? I know its A or C for sure.

tricky question...

so it says it is skidding, that means there is kinetic friction between the tire and the ground....NOT STATIC! that is the key concept to understand this question

Static is when the two objects are not moving, but are in contact with each other-as is the case when the car is rolled to a stop. the tire and the ground are just momentarily touching each other-no skidding there.

hope this helped.

 

[RocketSurgeon]

Yup it should be B.

Remember two types of friction 1) Static 2) Kinetic

Static - when the tire surface is NOT moving with respect to the surface of the road at the point of contact (This is the same as when a block is on an incline and is not sliding down due to friction)

Kinetic - when the tire surface is MOVING with respect to the surface of the road at the point of contact (This is the same as when a block is on an incline and is sliding down but is experiencing friction)

Also in the real world static friction is always greater than kinetic friction (I dont know if there are any exceptions but is is true for most materials)

A little side note if your car has ABS (Anti lock braking system) it uses the same principle to provide maximum friction by applying the brakes when your car is skidding multiple times so that your car can get optimum static friction

 

[Ghayoour]

Thank you both of you. I understand my mistake now.