2.4 Science In Action

Question: Archimedes’ Principle states:

Answer: The weight of the fluid displaced is always equalnto the buoyant force

Question: HYPOTHESIS #1 - If an object has a density greater than the liquid in which it is placed, I predict that it will:

Answer: Sink

Question: HYPOTHESIS #2 - If the buoyant force is greater than the weight of the object, I predict that it will:

Answer: Float

Question: Note that the test object initially sank into the water before bobbing back up. As the test object sank deeper into the water, what happened to the buoyant force?

Answer: It increased.

Question: With the test object at rest in the water, how does the buoyant force compare to the gravity force (represented by the yellow vector pointing downward from the bottom of the test object)?

Answer: The two forces are equal in strength.

Question: How much water is displaced by the floating test object?

Answer: 0.5 L

Question: What is the weight (w) of 1 L of water?

Answer: 9.8 N

Question: What is the weight (w) of the water displaced by the test object?

Answer: 4.9 N

Question: How does the weight of the water compare to the buoyant force?

Answer: They are equal, but opposite.

Question: How much water does the aluminum test object displace?

Answer: 1.0 L