Final answer:
The normal and frictional forces on car tires during circular motion can be determined through the forces on an inclined plane equation and centripetal force calculation. For a car on a banked curve with no skidding, the frictional force can be assumed to be just enough to provide the needed centripetal force for the given conditions.
Step-by-step explanation:
To solve for the normal force and the frictional force exerted by the pavement on the tires, we'll apply physics principles involving circular motion and forces on an inclined plane. The car's mass is different from the examples, but we will use the same method to solve for the normal and frictional forces.
Normal Force
The normal force on the tires exerted by the pavement can be found by considering the components of the gravitational force parallel and perpendicular to the surface of the banked curve. Since we are given the car's mass (750 kg) and the banking angle (15 degrees), we can calculate the normal force using the equation for the forces on an inclined plane, taking into account the centripetal force required for circular motion.
Frictional Force
The frictional force on a banked curve is zero if no skidding occurs and the speed is ideal. However, if the speed is not at the ideal level, static friction will act towards the center of the curve to provide the necessary centripetal force. In this case, since the car is not skidding at 85 km/h, the frictional force can be assumed to be sufficient to provide the centripetal force without exceeding the maximum limit set by the coefficient of friction.
The car's speed, converted to m/s, and the radius of the curve are used to calculate the centripetal force, which, along with the angle of the curve and the car's weight, allows us to solve for the normal force and determine the conditions for no skidding, hence no need for a frictional force. If the car were to take the curve at less than the ideal speed, we would need to consider the static friction available as well.