Sound Waves

These longitudinal waves that humans can detect have a frequency between 20 and 20,000 Hz.

(At 4:27 I should have said solids and liquids are denser so they travel quicker in these materials)

Echo Sounding in Deep Water

How fishermen detect fish and submarines don't bump into the sea floor. 

You may also be interested in...

Click below to return to your exam board


Coronavirus COVID-19 updates and daily lessons

GCSE Physics Online Recommended for Home Learning

The following organisations have recently recommended these resources to support students who are learning from home during the Covid-19 crisis.

Follow me!

  • YouTube
  • Instagram
  • Twitter