1. Bell-Ringers 12 June 2009

2. Bell-Ringer 12 June 2009 LT: Describe the forces acting on an object in a fluid. In your lab group, build three different sizes of aluminum foil boats that will float in your beaker of water. Push down on each boat with your finger -- what do you feel?

3. Floating forces 1 What experiences have you had with floating objects?

4. Floating forces 2 What experiences have you had with lifting sunken objects under water?

5. Some questions to answer… Do objects weigh the same in air as in the water? (Gather data to prove your point.) What is the weight of a block of wood in air and fully immersed in the water? (Gather data.) What is the weight of a piece of clay in air and suspended the water? (Gather data.)

6. Another question… If weight in the air is not the same as in water, why the difference? Draw the forces acting on a floating object.

7. Finding the “floaty” force. Weight in the air Wt air Weight on or in the water Wt water “Floaty” force? (buoyant force) F B FgFg FgFg FBFB