Answer:
Apparently the curve is not banked.
The maximum frictional force is -
Ff = m g * .5
Fc = m v^2 / R where Fc is the centripetal force that must be present in
order for the car not to slip.
.5 g = v^2 / R equating forces
v^2 = .5 R g = .5 ^ 1000 * 9.80
v = (500 * 9.80)^1/2 = 70 m/s
(about 230 ft/sec = 230/88 * 60 = 157 mph
