Students explore the biosphere and its associated environments and ecosystems in the context of creating a model ecosystem, learning along the way about the animals and resources. Students investigate different types of ecosystems, learn new vocabulary, and consider why a solid understanding of one's environment and the interdependence of an ecosystem can inform the choices we make and the way we engineer our communities. This lesson is part of a series of six lessons in which students use their growing understanding of various environments and the engineering design process, to design and create their own model biodome ecosystems.

This pathway explores the concept of forces. The basic techniques of vector algebra are discussed, which allows for an introduction to Newton's Three Laws of Motion, which describe how objects react when forces are applied to them. The pathway concludes with a series of questions for students to test their understanding.

Students explore materials engineering by modifying the material properties of water. Specifically, they use salt to lower the freezing point of water and test it by making ice cream. Using either a simple thermometer or a mechatronic temperature sensor, students learn about the lower temperature limit at which liquid water can exist such that even if placed in contact with a material much colder than 0 degrees Celsius, liquid water does not get colder than 0 °C. This provides students with an example of how materials can be modified (engineered) to change their equilibrium properties. They observe that when mixed with salt, liquid water's lower temperature limit can be dropped. Using salt-ice mixtures to cool the ice cream mixes to temperatures lower than 0 °C works better than ice alone.

E-learning site uses an example of "pushcarts on the beach" to demonstrate a monopolistically competitive market structure and how, as more firms enter the market, price, quantity, and deadweight loss are all affected.

A video lesson defining the basic vocabulary necessary to describe an ecosystem and its parts. Learn how the abiotic and biotic factors work together to form an ecosystem. [7:27]

Students explore the concepts of center of mass and static equilibrium by seeing how non-symmetrical objects balance. Using a paper cut-out shape of a parrot sitting on a wire coat hanger, they learn that their parrot exists in stable equilibrium — it returns to its balancing point after being disturbed. The weight of its tail makes the parrot balance upright. Give the parrot a push, and she knocks off balance, but swings back and forth until coming to rest in balance again.

Students will learn what causes reactions and what affects the rates of reaction through data collected by conducting several simulated experiments.

Explore what makes a reaction happen by colliding atoms and molecules. Design experiments with different reactions, concentrations, and temperatures. When are reactions reversible? What affects the rate of a reaction?

Principles of Macroeconomics 2e covers the scope and sequence of most introductory economics courses. The text includes many current examples, which are handled in a politically equitable way. The outcome is a balanced approach to the theory and application of economics concepts. The second edition has been thoroughly revised to increase clarity, update data and current event impacts, and incorporate the feedback from many reviewers and adopters. Changes made in Principles of Macroeconomics 2e are described in the preface and the transition guide to help instructors transition to the second edition. The first edition of Principles of Macroeconomics by OpenStax is available in web view here.

By the end of this section, you will be able to:
Contrast consumer surplus, producer surplus, and social surplus
Explain why price floors and price ceilings can be inefficient
Analyze demand and supply as a social adjustment mechanism

By the end of this section, you will be able to:

Explain demand, quantity demanded, and the law of demand
Identify a demand curve and a supply curve
Explain supply, quantity supplied, and the law of supply
Explain equilibrium, equilibrium price, and equilibrium quantity

By the end of this section, you will be able to:

Explain protectionism and its three main forms
Analyze protectionism through concepts of demand and supply, noting its effects on equilibrium
Calculate the effects of trade barriers

By the end of this section, you will be able to:

Predict shifts in the demand and supply curves of the labor market
Explain the impact of new technology on the demand and supply curves of the labor market
Explain price floors in the labor market such as minimum wage or a living wage

When a chemcial reaction occurs in a closed system, it will reach an equilibrium state in which reactants and products are produced at the same rate. This pathway provides resources to undestand the factors that affect chemical equilibrium.