The speed limit around a curve of radius 85 meters is 30 miles per hour. What angle should the curve be banked at if a car is to be able to go around the curve at that speed with no friction?

Question

The speed limit around a curve of radius 85 meters is 30 miles per hour.  What angle should the curve be banked at if a car is to be able to go around the curve at that speed with no friction?
Help!!!

Ms. Sue · Answer

Enough already! You haven't shown any indication that you've even tried to solve these problems!