$16.||$ For a normal car riding on tires with relatively flexible sidewalls, the weight of the car is held up$,$ in large measure, by the pressure of the air in the tires. If you look at one of your car$$s tires, you$$ll note that the tire is flattened slightly to make a rectangle where it touches the ground. The area of the resulting $$contact patch$$ depends on the pressure in the tires. To a good approximation, the upward normal force of the ground $($which we can assume is equal to $$ of the car$$s weight$)$ on this patch of the tire is equal to the downward pressure force on the patch. a$.$ Suppose you inflate your $2000$ kg car$$s tires to the recommended pressure, as measured by a gauge. The resulting contact patch is $18$ cm wide and $12$ cm long. What does the gauge read? b$.$ If you let a bit of air out of your tire, what happens to the area of the contact patch?