Courses
Teacher-curated, self-paced courses. Looking for a guided sequence through a full topic? See Learning Paths.
6 courses
Beats, Resonance and the Doppler Effect
Physics · High School (11–12) · Sound Waves and Hearing, Superposition and Standing Waves, Doppler Effect
FreeCh 14 · 3/3
Beats from two close frequencies, and how a tuner uses them. The resonance tube with its end correction. The Doppler effect for a moving source, a moving observer and both.
3Lessons12Problems3Python Labs1Question Set1Mock Test
Superposition and Standing Waves
Physics · High School (11–12) · Superposition and Standing Waves, Sound Waves and Hearing
FreeCh 14 · 2/3
The principle of superposition and the interference of two waves. Reflection at a fixed and at a free end. Standing waves and the normal modes of a string, and of pipes closed at one end or open at both.
3Lessons12Problems2Python Labs1Question Set1Mock Test
Travelling Waves and Wave Speed
Physics · High School (11–12) · Wave Motion, Sound Waves and Hearing
FreeCh 14 · 1/3
Transverse and longitudinal waves. The equation of a travelling wave, with its amplitude, wavelength, period and phase. The speed of a wave on a stretched string, and the speed of sound in a gas with Laplace's correction.
3Lessons12Problems2Python Labs1Question Set1Mock Test
Echoes, Hearing and Ultrasound
Physics · High School (9–10), General · Sound Waves and Hearing
FreeCh 5 · 3/3
Shout in front of a cliff, and your own voice comes back. Bats find insects in the dark, and ships find the sea floor, with sounds that we cannot hear. In this course we study echoes, the way the ear works, the range of hearing, and the uses of ultrasound.
3Lessons11Problems2Python Labs1Question Set1Mock Test
Describing a Sound Wave
Physics · High School (9–10), General · Wave Motion, Sound Waves and Hearing
FreeCh 5 · 2/3
A drum and a flute can play at the same loudness, but we never confuse them. A whistle is high and a bass drum is low. In this course we describe a sound with its wavelength, frequency and amplitude, and we use the wave equation to connect them with the speed.
3Lessons10Problems2Python Labs1Question Set1Mock Test
How Sound Is Made and How It Travels
Physics · High School (9–10), General · Sound Waves and Hearing
FreeCh 5 · 1/3
Touch your throat while you talk, and you feel it tremble. Every sound begins with something that vibrates. Here we see how a vibration makes a sound wave, why the wave needs a material to travel in, and how to find the distance of a lightning flash from the sound of its thunder.
3Lessons10Problems2Python Labs1Question Set1Mock Test