Final answer:
Without additional information such as the car's weight, it is not possible to calculate the maximum safe speed for a car to navigate a banked curve at a racetrack with the given conditions.
Step-by-step explanation:
The student asked for the maximum speed at which a car can safely navigate a curve at a racetrack with a radius of 900 m and a banking angle of 7.0° when the coefficient of friction is 0.70. To determine this speed, one can use the centripetal force equation and factor in the frictional force and gravitational force. By balancing the forces involved (centripetal force, gravitational force, and frictional force), we can calculate the maximum allowable speed before slipping occurs.
However, the question does not provide enough data to do a detailed calculation here. We would need either the weight of the car or an additional piece of information to calculate the normal force, which is needed to find the frictional force that defines the maximum speed a car could maintain while navigating the curve without slipping. Without more information or a specific formula, it is not possible to provide an accurate answer.