Question

a car is moving east along a straight, level road at a constant velocity. which forces form an action/reaction force pair? the force of the tires against the road and the force of the road on the tires the force of the engine on the car and the force due to friction on the car the normal force on the car and the force of the car pulling on earth the weight of the car and the force of the road pushing up on the car

Explanation:

According to Newton's third - law, action - reaction force pairs act on two different objects and are equal in magnitude and opposite in direction. The force of the tires against the road and the force of the road on the tires is an action - reaction pair as the tires push on the road and the road pushes back on the tires. The force of the engine on the car and the friction force on the car are not an action - reaction pair as they act on the same object (the car). The normal force on the car and the force of the car pulling on Earth is not the typical action - reaction pair related to the car's motion on the road. The weight of the car and the force of the road pushing up on the car are a balanced force pair (equal and opposite forces on the car), not an action - reaction pair.

Answer:

the force of the tires against the road and the force of the road on the tires