1. Chapter 14, Section 2 Buoyant Force

2. Buoyant Force
The upward force that fluids exert on all matter.

3. What causes it? Fluids exerts pressure on all sides of an object.
There is more pressure on the bottom because pressure increases with depth.
The water exerts a net upward force.

4. Archimede’s Principle
The buoyant force on an object in fluid is an upward force equal to the weight of the fluid that the object displaces.

5. Weight - Sink or Float??
If an object’s weight is greater than the buoyant force = sinks.
If an objects weight is equal or less than the buoyant force = floats

6. Buoying Up Buoyed up means to push back up.
A duck’s weight is = to 9N. If it dives underwater, The duck will displace more than 9N of water. What will happen to the duck?
Answer: 9N

7. Density - Sink or Float?
If an object’s density is less than the density of water = floats.
If an object’s density is greater than the density of water = sinks.

8. Steel Ships
Steel is 8 times more dense than water, so how do steel ships float?
They’re shaped like a bowl to increase the volume of the ship and decrease its overall density.

9. More Dense Than Air Most substances are more dense than air.
They contain more mass than an equal volume of air does.
So a rubber duck doesn’t float in air, but helium balloons do.

10. End of Ch.14-2