An engineer wants to design an oval racetrack such that 3.20 x 10³ lb racecars can round the exactly 1000 ft radius turns at 1.00 x 10² mi/h without the aid of friction. She estimates that the cars will round the turns at a maximum of 175 mi/h. Find the banking angle θ necessary for the race cars to navigate the turns at 1.00 x 10² mi/h without the aid of friction.