[onewhippedpuppy]

1. Dynamic pressure increases with velocity, and force from pressure = Pressure * Area. Your hand perpendicular to the ground has more surface area than when parallel, so more force is experienced.

2. NASCAR sucks. Cars only go left, so more frontal surface area on the left side would tend to yaw the car, increasing it's tendacy to turn left.

3. The tire gauge measures the difference between the ambient (atmospheric) pressure and the air pressure inside the tire. True pressure is the pressure inside the tire + ambient pressure.

4. Anti-freeze raises the boiling point of the water.

5. No idea, I can't picture what is described. I would guess you find the volume, then multiply volume * air density to find the mass of the air. Since it asks how much the air "weighs", multiply mass * the force of gravity to find weight force.
3.