- #1
Zoolog
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Hello,
I have a question from a conceptual problem in my textbook as follows:
A car is moving north and speeding up to pass a truck on a level road. The combined contact force exerted on the road by all four tires has vertical component 11.0 kN downward and horizontal component 3.3 kN southward. The drag force exerted on the car by the air is 1.2 kN southward. What is the net force acting on the car?
The answer given in the textbook has the normal and gravitational forces cancelling out; and the net force being 2.1 kN northward on the car; with static friction exceeding the drag force by that much. My confusion is with the source of the friction. If the tires exert 3.3 kN south on the road, and the road exerts a force of 3.3 kN north on the tires where does the friction come in? Is the friction a force in addition to the equal and opposite force? Does the static friction on the car come from moving with the tires to resist this force? Or is the static friction on the car from the road resisting the tires motion?
Thank you
I have a question from a conceptual problem in my textbook as follows:
A car is moving north and speeding up to pass a truck on a level road. The combined contact force exerted on the road by all four tires has vertical component 11.0 kN downward and horizontal component 3.3 kN southward. The drag force exerted on the car by the air is 1.2 kN southward. What is the net force acting on the car?
The answer given in the textbook has the normal and gravitational forces cancelling out; and the net force being 2.1 kN northward on the car; with static friction exceeding the drag force by that much. My confusion is with the source of the friction. If the tires exert 3.3 kN south on the road, and the road exerts a force of 3.3 kN north on the tires where does the friction come in? Is the friction a force in addition to the equal and opposite force? Does the static friction on the car come from moving with the tires to resist this force? Or is the static friction on the car from the road resisting the tires motion?
Thank you