Answer
The maximum speed that the car can go around the turn is 24 m/s. Yes, this speed is independent of the mass.
Work Step by Step
As long as the speed is not too fast, the force of static friction can provide the required force for the car to go around the curve.
$m\frac{v^2}{r} = F_f$
$m\frac{v^2}{r} = mg ~\mu$
$v = \sqrt{rg\mu}$
$v = \sqrt{(90.0 ~m)(9.8 ~m/s^2)(0.65)}$
$v = 24 ~m/s$
The maximum speed that the car can go around the turn is 24 m/s. Yes, this speed is independent of the mass.
