A curve of radius 144 m is banked at an angle of 12°. An 852-kg car negotiates t
ID: 1282206 • Letter: A
Question
A curve of radius 144 m is banked at an angle of 12°. An 852-kg car negotiates the curve at 87 km/h without skidding. Neglect the effects of air drag and rolling friction. Find the following. (a) the normal force exerted by the pavement on the tires Changed: Your submitted answer was incorrect. Your current answer has not been submitted. kN (b) the frictional force exerted by the pavement on the tires Incorrect: Your answer is incorrect. kN (c) the minimum coefficient of static friction between the pavement and the tires
Explanation / Answer
a) m*g*cos12
b) Centripetal force is required to have the car follow the curve. The value is given by
Fc = m*v^2/r
The banking of the road provides some, given by
F1 = m*g*sin12
The friction force, Ff, must supply the rest of the required Fc.
You know what Ff must be. The friction formula is
Ff = mu*N
where you calculated N for part a. Solve for mu.