9.- Calculate the total support surface of the tyres of a car with a mass of 1500 kg. with a pressure of "2.2 kg"'- in everyday language-. 

N.B. Look in the units section for the meaning of 2.2 kg. Solve the exercise in your notebook and check the solution dragging the mouse over the "solutions" control. Compare your way of solving the problem with the explanation in "Answer".