1. Flotation A floating object displaces a weight of fluid equal to its own weight.

2. Flotation

3. Buoyancy in a Gas Since air gets less dense with altitude, the buoyant force decreases with altitude. So helium balloons don’t rise forever!!!

4. Bernoulli’s Principle

5. For an ideal fluid, and increase in the speed of the fluid will result in a decrease of the pressure. Flow is faster when the pipe is narrower Put your thumb over the end of a garden hose Energy conservation requires that the pressure be lower in a gas that is moving faster.

6. Bernoulli’s Principle When the speed of a fluid increases, internal pressure in the fluid decreases.

7. Q 1 = A 1 V 1 A1A1 V 1 -> Q 2 = A 2 V 2 A 1 V 1 = A 2 V 2 A 2 V 2 -> At which point is the pressure greatest – A 1 or A 2 ?

8. Bernoulli’s Principle What happens to the pressure above the wing?

9. Bernoulli’s Principle Why the streamlines are compressed is quite complicated and relates to the air boundary layer, friction and turbulence.

10. Bernoulli’s Principle