The document discusses Archimedes' discovery of buoyancy and its principles. It explains that Archimedes discovered that objects float or sink based on the amount of water they displace. It also outlines Archimedes' principle of buoyancy - that the buoyant force on an object equals the weight of the fluid it displaces. Finally, it briefly describes how submarines and airships are able to control their buoyancy through changing the amount of water or air they displace.

1. Pgs. 160-164 For Student Use Only

2. Archimedes discovered why gases float. Archimedes discovered why certain objects will float and certain objects will sink.

3. Different objects displace different amount of water. Bouyancy= the tendency for an object to float when it is placed in a fluid. An object in water feels lighter and this is called bouyancy.

4. What is buoyant force? Archimedes principle of bouyancy: states the weight lost by an object immersed in a fluid is equal to the weight of the fluid displaced

5. Why do ships float but solid steel sinks? Water pushes up with a bouyant force Objects are pulled down with the force of gravity. Objects size and mass help determine the bouyant force.

6. What is a submarine? All of the above A boat Toy kids play with Ship that sinks A ship that can manuver on the surface or dive below

7. How do submarines and airships work? Submarine- *On the surface- displaces equal volume. *To submerge- takes in water to displace less volume Airships- *Float better on the surface of the Earth due to the thicker air

8. What makes all these devices work? Archimedes principle- object displace a volume equal to their own. What are constraints in subs and airships? Subs- hull Airship- altitude NOTE: