Science 3
Goals:
Students will be able to identify the reason why an object sinks, floats, or remains neutrally bouyant.
Students will recognize that objects do not sink or float due to their weight/mass but rather as a result of their density.
Materials:
Computer lab or cart
https://phet.colorado.edu/sims/density-and-buoyancy/density_en.html
Process:
- Assess prior knowledge by asking students what types of objects sink or float
- Ask students to come up with a rule regarding whether an object sinks or floats
- Have the class log on to the computers and navigate to https://phet.colorado.edu/sims/density-and-buoyancy/density_en.html
- Have students begin on the blocks of the same mass activity and record which colours sink or float
- Ask students if this agrees with their rules. If not, what else might explain why some blocks sink and others do not
- Next have the students complete the same process for blocks of the same size, record their results, and see if they agree with their new rule.
- Have students open the custom block option and attempt to three different materials to float in the middle of the water. What do their 3 floating objects all have in common?
- As a class, come up with a new rule to explain bouyancy as a result of an object having the same density as the fluid in which it is sitting.
- Explain the terms positive, neutral, and negative bouyancy
- Model calculating denstiy by dividing mass by volume. Grade 3’s will likely need calculators
- Return to the simulaitons and have the students students check this new theory using the blocks of same density setting.
- Extension: have students use the mystery blocks option, the demonstrated calcuation, and the density reference chart in the simulaiton to discover the identity of each of the mystery blocks.