This unit launches with a slow-motion video of a speaker as it plays music. In the previous unit, students developed a model of sound. This unit allows students to investigate the cause of a speaker’s vibration in addition to the effect.

Students dissect speakers to explore the inner workings, and engineer homemade cup speakers to manipulate the parts of the speaker. They identify that most speakers have the same parts–a magnet, a coil of wire, and a membrane. Students investigate each of these parts to figure out how they work together in the speaker system. Along the way, students manipulate the components (e.g. changing the strength of the magnet, number of coils, direction of current) to see how this technology can be modified and applied to a variety of contexts, like MagLev trains, junkyard magnets, and electric motors.

This simulation lets you see sound waves. Adjust the frequency or volume and you can see and hear how the wave changes. Move the listener around and hear what she hears.

This simulation lets you see sound waves. Adjust the frequency or volume and you can see and hear how the wave changes. Move the listener around and hear what she hears.

This lesson is the first of three on the topic. It is designed so that teachers can introduce new concepts to students engagingly and educationally. You can teach this lesson to beginner, elementary English speakers or use it as a review for more intermediate-level speakers. This lesson can also be used during individual and group lessons. Keep in mind that age does not necessarily correlate with a learner’s level of proficiency in English.Before this lesson, students should have prerequisite knowledge of the present simple tense, present continuous tense and the ability to count syllables.If you want additional lesson plans and support, including teachers’ notes, be sure to register for a free Off2Class account.

What are infinitives? When teaching infinitives it is especially important to know what they are. Infinitives are the base form of verbs. Infinitives are often formed by placing the word “to” and then following it with a verb. For example, “to buy/to work/to shop”. Keep in mind that a bare infinitive does not have the word “to” preceding it. Sometimes English speakers use infinitives as objects in sentences. Infinitives can also be used as a subject at the beginning of some sentences; they can be used as adverbs to modify verbs as well. Finally, they can be used as adjectives and/or complements to adjectives. As the lesson progresses, you will introduce the different uses of infinitives to students. Though teaching infinitives seems difficult, this lesson makes it fun and clear.If you want additional lesson plans and support, including teachers’ notes, be sure to register for a free Off2Class account.

Make waves with a dripping faucet, audio speaker, or laser! Add a second source or a pair of slits to create an interference pattern.