Take into account that due to the speed of the car is constant, the net force on the car is the force due to the centrifugal force, which is given by the following formula:
[tex]F=ma_c=m\cdot\frac{v^2}{r}[/tex]where:
m: mass of the car = 1200 kg
v: speed = 5.5 m/s
r: radius of the circular trajectory = 65 m
replace the previous values of the parameters into the formula for F:
[tex]F=1200kg\cdot\frac{(5.5m/s)^2}{65m}=558.46N\approx558N[/tex]