Based on what they have already learned about friction, students formulate hypotheses concerning the effects of weight and contact area on the amount of friction between two surfaces. In the Associat...
... more

Based on what they have already learned about friction, students formulate hypotheses concerning the effects of weight and contact area on the amount of friction between two surfaces. In the Associated Activities (Does Weight Matter? and Does Area Matter?), students design and conduct simple experiments to test their hypotheses, using procedures similar to those used in the previous lesson (Discovering Friction). An analysis of their data will reveal the importance of weight to normal friction (the friction that occurs as a result of surface roughness) and the importance of surface area to the friction that occurs between smooth surfaces due to molecular attraction. Based on their data, students will also be able to calculate coefficients of friction for the materials tested, and compare these to published values for various materials.
... less

This lesson introduces students to the important concept of density. The focus is on the more easily understood densities of solids, but students can also explore the densities of liquids and gases. ...
... more

This lesson introduces students to the important concept of density. The focus is on the more easily understood densities of solids, but students can also explore the densities of liquids and gases. Students devise methods to determine the densities of solid objects, including the method of water displacement to determine volumes of irregularly-shaped objects. By comparing densities of various solids to the density of water, and by considering the behavior of different solids when placed in water, students conclude that ordinarily, objects with densities greater than water will sink, while those with densities less than water will float. Density is an important material property for engineers to understand.
... less

This lesson focuses on how food packages are designed and made. Students will learn three of the main functions of a food package. They will learn what is necessary of the design and materials of a ...
... more

This lesson focuses on how food packages are designed and made. Students will learn three of the main functions of a food package. They will learn what is necessary of the design and materials of a package to keep food clean, protect or aid in the physical and chemical changes that can take place in a food, and identify a food appealingly. Then, in the associated activity, the students will have the opportunity to become packaging engineers by designing and building their own food package for a particular type of food.
... less

In this lesson, students will learn that minerals are a necessary part of our diet. They will learn that different minerals have different functions in the body. More specifically, they will discove...
... more

In this lesson, students will learn that minerals are a necessary part of our diet. They will learn that different minerals have different functions in the body. More specifically, they will discover that iron is necessary to carry oxygen around the body. In the associated activity, students will design a process that removes the most iron from the cereal.
... less