1. Density and Buoyancy

2. Float? Whether an object will float or not is dependent on the density of the object and the density of the fluid.

3. Density

4. Float vs. Sink An object will float if it is less dense than the liquid. It will sink if it is more dense than the liquid.

5. Archimedes http://www.dctech.com/eureka/archimedes/crown/

6. Archimedes’ Discovery A submerged object displaces a volume of fluid equal to its own volume

7. Additional Fact A floating object also displaces a volume of fluid, but one less than its total volume

8. Archimedes’ Principle Any floating or submerged object experiences an upward force equal in magnitude to the weight of the fluid displaced.

9. Buoyant Force

10. Example A 0.1 m 3 object is submerged in sea water (density of 1030 kg/m 3 ). What is the buoyant force on the object?

11. Apparent Weight ????.?? The apparent weight of a submerged object is found by subtracting the F buoy from the actual weight.

12. Problem A rock of density 4500 kg/m 3 is submerged in a pool filled with water (density of 1000 kg/m 3 ). The weight of the rock is 225 N. What force is required to lift the rock from the bottom of the pool?

13. Problem #2 A ball (density of 500 kg/m 3 ) is floating in water (density of 1000 kg/m 3 ). The radius of the ball is 0.25 m. What is the volume of water displaced?