Question

Suppose the posted designated speed for a highway ramp is to be 30 mph and the radius of the curve is 700 ft. At what angle must the curve be banked? No Friction

Answer 1

4.92°

Step-by-step explanation:

The banking angle θ = tan⁻¹(v²/rg) where v = designated speed of ramp = 30 mph = 30 × 1609 m/3600 s = 13.41 m/s, r = radius of curve = 700 ft = 700 × 0.3048 m = 213.36 m and g = acceleration due to gravity = 9.8 m/s²

Substituting the variables into the equation, we have

θ = tan⁻¹(v²/rg)

= tan⁻¹((13.41 m/s)²/[213.36 m × 9.8 m/s²])

= tan⁻¹((179.8281 m²/s)²/[2090.928 m²/s²])

= tan⁻¹(0.086)

= 4.92°