Answer:
u = 0.30
v = 29km/h = 8.1 m/s
Fc = Ff
Fc = (mv^2)/r
Ff = u(Fn)
Fn = mg
Ff = u(mg)
(mv^2)/r = u(mg)
The mass, m, cancels out, leaving:
(v^2)/r = u(g)
Plugging in what we know, we get:
(8.1^2)/r = .3(9.8)
65.6 = 2.93r
r = 22.4 m
So, the circle must have a radius of at least 22.4 meters.