A 60 minute lesson in which students will explore the force of buoyancy.
Prior to conducting the lesson, review the procedure and the equipment required for the experiment.
Display slide 14 of the Push and Pull PowerPoint. As a class, brainstorm some possible answers to the questions on the slide.
Demonstrate the investigation on slide 17 for the class. Encourage the students to share their ideas about why the ball pops up when it is pushed down into the water.
Display and discuss slides 15-16. Encourage the students to suggest situations where the weight force down is equal to the upward push of water (items that float) and situations where the weight force down is larger than the upward push of water (items that sink).
What are the two things that effect whether an object floats or sinks?
Why does a bowling ball sink when you place it into a bucket of water?
Why does a balloon float when you place it into a bucket of water?
Provide the students with a copy of the Push and Pull Inquiry Task. Read the instructions for the floating task to the students and answer any questions they may have.
Support the students to complete the first two boxes (ask a question and make a prediction) on the Scientific Method Worksheet. Encourage the students to share their predictions.
Place the students into groups and assign a group leader to collect the necessary equipment. Allow the students to complete the inquiry task in small groups. Monitor and support the students as required.
Support the students to complete the last two boxes (observe and record results and method) on their worksheets.
Discuss the results of the inquiry task as a class. Ask the students:
What happened when you put the ball of blue tac into the water?
What happened when you put the flattened strip of blue tac into the water?
Why do you think this happened?
Encourage fast finishers to repeat the inquiry using a different material e.g. cardboard.
Allow less confident students to be assisted by their peers during group work.