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Island Explorers Curriculum Home

 

Unit 2

Lesson Plan 1

Lesson Plan 2

Lesson Plan 3

Lesson Plan 4

Lesson Plan 5

Lesson Plan 6

Lesson Plan 7

Concepts/Objectives | Vocabulary/Background | Activity | Extension

 

Lesson Plan 3

 (Activity)

 

"SINKING SLOWLY"

ACTIVITIES:

"SINKING SLOWLY"

Before Class:
This is a great, messy activity. It is particularly good for a warm day when the class may be naturally restless and ready for some excitement. The best way to finish this class is with a contest so you may want to think about some possible prizes (coupons for lost homework, small toys).

During Class:

  1. Start with observations of zooplankton and phytoplankton. Observe their shapes, projections and behaviors. Most plankton are heavier than water and tend to sink. Ask how they might stay up in the water. Make a list of the students' observations.
  2. Some of the students should notice that many plankton have long projections or antennae or hairs. Have them speculate on how these would affect movement through water. Could the students run through water faster with their own arms spread out or folded up?
  3. Now the students are going to see if they can make a model phytoplankton or zooplankton which will sink slowly. Since "thrashing" or swimming is not possible in a non-mechanical model, they must concentrate on designing a plant or animal that is just barely heavier than water and that slows its rate of sinking by increasing its resistance to movement through water with long projections or hairs or that sinks slowly because it swings back and forth as it goes down. Have selections of materials and buckets of water available around he room for design and testing. Use stopwatches to time the speed of sinking. Set a time limit for experimentation and announce a contest for the slowest sinking animal or plant at the end of that time.
  4. The best way to have the contest is to gather around a large glass aquarium where everyone can see. A big trash can of water or a large bucket will work, but you cannot give everyone a good view. In that case have several students help you as judges. You can time each separately, but it will be more exciting if pairs of phytoplankton or zooplankton are released to "reverse race" their way down. Put both on a sheet of cardboard so they can be tipped in at the same time for a fair start. The SLOWEST from each pair goes into a second heat and so on until you get down to two.
  5. Have the students analyze what they think made each of the last two models winners. Then have them vote on which they think will win the grand prize for slowest overall based on their analysis. Do the final test and distribute prizes. Note: The plankton must SINK not float. They may not sink because they get wet slowly, but rather, because they are heavier than water from the start.

Results:
Something just barely heavier than water with lots of projections should win unless a student can produce a flat, pie pan shaped object that makes big swings from side to side as it descends.

Discussion:

  1. Have students discuss why certain models floated and others sank.




Concepts/Objectives | Vocabulary/Background | Activity | Extension