Floating and Sinking

by

Richard Jervey

Comments || Introduction || Content Outline || Concept Map || Learning Objectives || Activities || Teaching Strategies || Resources || Assessment || Notes to a Teacher

Comments

Introduction

This fifth grade unit explores the factors that determine the buoyancy of objects through a hands on, discovery approach.

Content Outline

• Several factors effect buoyancy.
• Liquids exert a buoyant force on objects therein.
• The buoyant force of liquids is greater on larger objects.
• The amount of water displaced by and object is directly related to the volume of the object.
• Buoyant force makes objects appear to weigh less in water.
• Objects that weigh more than an equal volume of water will sink.
• Objects that weigh less than an equal volume of water will float.
• Salt water is heavier (more dense) than an equal amount of fresh water.
• Buoyancy of an object varies with the density of the liquid.

Concept Map

Learning Objectives

Students will learn concepts behind the floating of objects.

Students will use scientific methodology.

Students will develop inquiry strategies.

Activities

• Students predict whether a collection of objects will float or sink, and then test those items.
• Students calibrate spring scales and weigh objects.
• Students reform clay to try to make it float.
• Students design, construct, and test aluminum foil "boats" to see which will float the greatest load.
• Students measure buoyant force.
• Students measure displacement of water.
• Students compare weight of fresh water and salt water.
• Students test floatability of objects in salt water.

Teaching Strategies

Resources

Books

1. Bosak, Susan. (1991). Science Is... Scholastic Canada Ltd.:Canada.
2. Daniels, Kari. (1994). Junior science experiments on file. Facts On File, Inc. : New York.
3. Liem, Tik. (1987). Invitations to science inquiry. Science Inquiry Enterprises: California.

   On-line

   1. TOPScience

   1. Includes activity using liquids of different densities causing them to layer. Also includes activity with ice melting in cooking oil .

   2. Biffa. HTI Environmental Trust Fund

   1. Activity that uses three liquids that layer and three objects that float at the different levels. Submarine activity is also of interest.

   3. Swedish STC classroom

   1. View a Swedish classroom as it works on the Floating and Sinking unit. An e-mail address is also provided for correspondence.

   4. Evaluations of Hands-on Kits

   This site is not complete but may be of use in the future. It contains evaluations of various STC and Insights Kits.

   5. Inventing Density

   You will find an interesting account of teachers being taught about density through a contructivist approach.

Assessment

Notes to a Teacher

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