What is the maximum speed at which a car can safely travel around a circular track of radius 75.0 m if the coefficient of friction between the tire and road is 0.200?

A) 3.87 m/s

B) 12.1 m/s

C) 15.0 m/s

D) 147 m/s

B) 12.1 m/s

Explanation:

Sum of the forces in the y direction:

∑F = ma

N - mg = 0

N = mg

Sum of the forces in the radial direction:

∑F = ma

F = m v² / r

Nμ = m v² / r

Substituting and solving for v:

mgμ = m v² / r

gμ = v² / r

v = √ (gμr)

Given that μ = 0.200 and r = 75.0 m:

v = √ (9.81 m/s² * 0.200 * 75.0 m)

v = 12.1 m/s