1. Students will understand the concept of buoyancy, displacement, and mass.

2. Students will measure the buoyant effect of water.

1. Dish tubs filled with water. (One per table)

2. Material to make boats. (Paper, wood, tin foil etc.)

3. Small weights to weigh down the boat.

4. balance, 250 ml beaker, overflow can, paraffin block, string, spring scale, metal object.

5. Physical Science Silver Burdett and Ginn pg. 290-291.Possible books to use: Build and Sail your Own Boat by Norman Dahl, London, S. Paul 1 g78.

This lesson requires 1.5-2.5 hours. It will take 30 minutes to one hour to do the activity in steps 3-13 and about 1-1.5 to do the activity in 14-16.

Introduction: Students will learn the rules of buoyancy and experiment making their own boat.

Step 1 Students need to brainstorm from previous knowledge what they know about how to make a boat float. When ideas stop flowing, have students look in the encyclopedia or dictionary or another resource available in the classroom.

Step 2 Teacher will discuss and lecture about the buoyant force and Archimedes' principle.

Step 3 Draw a data table. (Attached)

Step 4 Use a balance to find the mass of an empty 250 ml beaker. What is the mass of the beaker?

Step 5 Fill an overflow can with enough water to bring the level of water in the can to the spout. Place the beaker under the spout.

Step 6 Tie a piece of string around a paraffin block. Attach the free end of the string to the hook on a spring scale.

Step 7 Use the spring scale to find the weight of the paraffin block. Record your answer in the data table.

Step 8 Lower the paraffin block into the overflow can. Make sure that the beaker catches all the water that comes out of the spout. Take care not to touch the bottom or sides of the overflow can.

Step 9 Record the weight of the paraffin block while it is suspended in water.

Step 10 Find the mass of the beaker and the water. What is the mass of the beaker and the water? What is the mass of the water displaced?

Step 11 Calculate the weight in newtons of the water displaced. Record your answer.

Step 12 Repeat steps 5-11, suing a metal object (such as a nail or a weight with a hook) instead of the paraffin.

Step 13 Students will answer the following questions: How does the weight of each object in air compare with its weight in water? How does the weight loss of each object compare with the weight of the water it displaced?

Step 14 Students will be given instruction on the procedures to go about making their boat float. Hand out materials (tubs with eater, tin foil, weight (you can use sand or salt if you do not have small weights), Share tubs between 2 or 4 students.) Students will first be asked to just make a boat that: floats. Teacher will interview and observe students at work.

Step 15 Students will be asked to see how much weight their boats can hold and still float. Put measurable amounts of salt or sugar or small weights into the boats. The students may find they need to reconstruct their boat to make it able to hold more. Allow time for students to experiment, trial and error.

Step 16 Discuss what makes a good boat, how do ships carry cargo, and review the rules of buoyancy, displacement, and mass.

1. Students will make a boat float. (Criteria for success = Teacher will observe and interview each student on their process and final "boats")

2. Students will record in their journal their conclusions to what makes a good boat float by explaining the concepts of buoyancy, displacement, and mass. (Criteria for success - Students will record their process and procedure of completing the boat. See journal rubric.)

1. Science - Buoyant Force

2. Math - Calculating the weight of the water displaced.

1. Students could try the experiment with other objects besides paraffin or metal.

2. Students could study or research more about Archimedes classic experiment.

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