hello, im new and im really just starting out in physics, but i have a question that my text book doesn't address yet gives some problems on. This is a sample problem, it deals with banking during circular motion. "Circular freeway entrace and exit ramps are commonly banked to handle a car moving at 13 m/s. To design a similar ramp for 26 m/s, one should: A) increase radius by a factor of 2 B) decrease radius by a factor of 2 C) increase radius by a factor of 4 D) decrease radius by a factor of 4 E) increase radius by a factor of squareroot of 2 the only circular motion equations i have are a= v^2/R and F=m V2/R Does anyone know any equations that i can use to solve this? i have other problems like this but give angles of banking, and so does anyone know other equations i can use to figure these problems out?