Buoyancy
1. Use the PheT simulation found at:
https:
phet.colorado.edu/sims/density-and-buoyancy
uoyancy_en.html
2. Select the simulation labeled “Intro”. Weigh each block and record your answers in the table below.
Block
Weight in ai
Weight in wate
3. Select “gravity” and “Buoyancy” as well as “force values” in the chart at the bottom to show these forces. Use these to draw a force diagram for the
icks in the water. Label the strength of the gravitational and buoyant forces on your diagram.
4. Based on the force diagram, explain why the weights of the blocks are different in the water compared to their weights in air.
5. If you change the fluid to oil instead of water, what changes do you observe? Can you explain them?
6. Now select the simulation “Buoyancy Playground”. Select to show the “force values,” “Gravity,” and “buoyancy”. Complete the chart below.
Material
Weight in ai
Weight in wate
Buoyant force
Density
Sink or float?
7. Explain the results in the table using what you know about the force of buoyancy. Why do some materials sink and others float (hint: consider density)?
8. When the blocks sink, what happens to the water level? Why does this happen?
9. Now select “My Block” in the chart on the top left. This allows you to choose the mass and volume of the block freely. Can you find a combination that will float half submerged in water? Record your value of density here: ________________________________.
10. Change the fluid using the slider on the bottom to select “air,” “gasoline,” “olive oil,” and “honey.” What happens to the block as the liquid changes? Explain why.
11. Summarize what you have learned about the buoyancy force and floating here XXXXXXXXXXwords minimum)
8.