$2.$ During a rainy day, a car is driven at a uniform speed v along a circular race course with radius R$=500$ m$.$ The race course is banked at an angle $25\mathrm{.}0$o$.$ Suppose at some point the race course is very slippery so that the static friction coefficient between the tire and the road is nearly zero, what is a safe speed v for the car not to slip sideways? A$.$ v should be as small as possible B$.$ v$=47\mathrm{.}8$ m$/$sec C$.$ v$=66\mathrm{.}6$ m$/$sec D$.$ If the friction coefficient is zero, the car is going to slip sideways no matter at what speed E$.$ v is dependent on the mass of the car, hence there is not enough information to determine the safe speed