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Physics at Work. What do planes and car racing have in common?. Airfoils. Bernoulli Principle: air moves faster over the top, so exerts less pressure Generates LIFT Also generates DRAG. Lift. Drag. Bernoulli principle. Faster moving air (or any fluid) exerts less pressure. More Airfoils.
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Physics at Work What do planes and car racing have in common?
Airfoils • Bernoulli Principle: air moves faster over the top, so exerts less pressure • Generates LIFT • Also generates DRAG Lift Drag
Bernoulli principle • Faster moving air (or any fluid) exerts less pressure
More Airfoils • Airfoils work by manipulating airflow, not just the Bernoulli Principle • Not all airfoils look the same • Manipulate airflow through angle of attack(answers question: how can planes fly upside down?) – further discuss angle of attack
Airfoils on cars • Airfoil is upside down • “Lift” is now called “Negative Lift” when the airfoil is upside down • On a car, it’s specifically called “Downforce” Drag “Negative Lift” “Downforce”
Forces on cars • To discuss: propulsion comes from friction of the wheels against the ground as they spin • Also review: what keeps a car from sliding off the road during a turn? Force of Earth on Car • To discuss: what causes the drag? Not friction against the road, but at the axels, as well as air pressure Drag Propulsion Weight of Car and Passengers
Forces on cars with airfoils • The addition of the “downward lift” increases the force of the earth on the car • Remember: • Ff = µ * FN Force of Earth on Car Drag from Airfoil Drag Propulsion “Downforce” • Discuss: How does this affect how fast you can go? • How does it affect the car in turns? • Make sure to discuss disadvantage of increase in drag Weight of Car and Passengers