Learners study the theory of operation for a ratio pyrometer that measures temperature. A short quiz completes the activity.

In this interactive object, learners simplify ratios and solve problems using proportions. All terms are defined.

In this animated object, learners examine the ratio control method used in automation when two or more ingredients are mixed. A brief quiz completes the activity.

In this screencast, learners examine the concept of gear ratios. The number of teeth, diameters, and velocity relationships are discussed and calculated using linear ratio equations.

In this animated object, learners examine formulas for displacement and velocity ratios. They also view examples and calculate velocity and the velocity ratio.

Students examine how voting rates are determined and how those rates change depending upon the population being studied. A brief quiz completes the activity.

In this learning activity you'll review sample problems and practice simplifying ratios.

In this learning activity you'll calculate exchange rates to determine the impact of prices of exports and imports.

Students read how to determine and calculate the void ratio for a given sample of soil or aggregate based on the weight-volume relationship.

In this learning activity you'll test your knowledge of global rates for marriage.

In this learning activity you'll test your knowledge of global rates for births.

In this learning activity you'll evaluate the Sine, Cosine, and Tangent ratios of a right triangle.

This content gives the student a text and photo overview of feed rate calculations.

Learners use the coefficients in a balanced equation to develop the mole ratios of reactants and products involved in the reaction. Five interactive examples illustrate the method, and students test their knowledge by working four problems.

Students read descriptions of the voltage, current, and turns ratios of the primary and secondary coils for a transformer in this interactive lesson.

In this animated and interactive object, learners examine why the voltage produced by an AC drive must be increased when its frequency is increased due to inductive reactance.

The Animal Welfare Act, or AWA, gives protection to animals used in research, education, and entertainment. Explore ethical use and some of the current alternatives in this module.

Learners view an animated explanation of why an adjustment of the output voltage by an AC drive is required to maintain a constant torque as the frequency is varied.

In this animated activity, learners examine the circuitry in a DC variable speed drive that causes the motor to accelerate or decelerate at slow rates. This learning object has audio content.

In this screencast, learners examine the steps of carbohydrate digestion.