Take into account that the static friction supplies the centripetal force, then, you can write:
[tex]F_r=m\frac{v^2}{r}[/tex]where,
m: mass of the truck = 1700 kg
v: speed of the truck = 20 m/s
r: turning radius = ?
Fr: maximum frictional force = 12,000 N
Solve the equation above for r, replace the values of the other parameters and simplify:
[tex]r=\frac{mv^2}{F_r}=\frac{\left(1700kg\right)\left(20\frac{m}{s}\right)^2}{12000N}\approx56.67m[/tex]Hence, the turing radius of the car is approximately 56.67m
