Sample lesson · Physics · Class 9
Sound is a longitudinal wave.
Sound is a longitudinal wave. It travels as squeezes and stretches in the air: the particles move back and forth along the direction the wave travels, not up and down.
آواز ایک طولی لہر ہے۔ ہوا کے ذرّات لہر کی سمت میں آگے پیچھے حرکت کرتے ہیں، اوپر نیچے نہیں۔
Transcript
A slinky is stretched across a table. One end is pushed in and out. A bunch of tightly packed coils, the compression, moves along the slinky, followed by a gap where the coils are spread out, the rarefaction. The coils themselves only move back and forth.
Timed practice
20 minutes for 12 questions
See every setting, by what you need
When a timer ends, deaf and hard-of-hearing students get a visual alert, not just a chime.
