The answer is : Open circuit
I would say friction because it requires to surfaces in order for the force to take place
correct me if I'm wrong.
You would use answer 2O g/cm3
Torque = r x F
|F| = mg = 60 * 10 N = 600 N ( assuming g ~ 10m/s^2)
distance of fulcrum = torque / Force = 90/600 m = .15 m.
It would be helpful if you gave me a bit more information on what the cars speed is