The magnitude of static friction is
<em>f</em> = <em>mv</em> ²/<em>r</em>
(i.e. the net force acting on the car parallel to the road points toward the center of the curve)
while the net vertical force must be
∑ <em>F</em> = <em>n</em> - <em>mg</em> = 0
because the car is otherwise in equilibrium. Then
==> <em>n</em> = <em>mg</em>
==> <em>f</em> = <em>µn</em> = <em>µmg</em> = <em>mv</em> ²/<em>r</em>
==> <em>µ</em> = <em>v</em> ²/(<em>rg</em>)
We have
<em>v</em> = 101 km/h ≈ 28.1 m/s
<em>r</em> = 110 m
<em>g</em> = 9.80 m/s²
so that
<em>µ</em> = (28.1 m/s)² / ((110 m) <em>g</em>) ≈ 0.730