The Physics 2 Tutor: Learning by Example DVD series covers thermodynamics, oscillations & waves in physics through step-by-step example problems. Emphasis is placed on giving students confidence in their skills by gradual repetition so that the skills learned are committed to long term memory. Lessons cover the speed of sound waves, including how sound waves propagate through the air and how the speed of sound depends on the material through which the sound is propagating. Grades 9-12. 45 minutes on DVD.