1. The problem statement, all variables and given/known data A car drives along a curved track. The frictional force exerted by the track on the car is: a. greater than the frictional force exerted by the car on the track b. directed radially outward c. opposite in direction to the frictional force exerted by the car on the track d. zero if the car's speed is constant e. dependent on the radius of the track 2. Relevant equations mV2/R = Centripetal force Ffr = Fc if the car is to not slide 3. The attempt at a solution So the track must exert a frictional force on the car equal to its centripetal force as it rounds the circle to prevent it from slipping. And this centripetal force is dependent on the radius of the track R. So from this I think the answer could be E. But also, between any two objects A and B, the friction A exerts on B is equal and opposite in direction to the frictional force B exerts on A. So from this I think the answer could be C. The book says the answer is C. But I want to know why it can't be E.