Question #14f5a
1 Answer
Jan 15, 2018
There’s aren’t many ...
Explanation:
Sound (and ultrasound of course) are the best (simplest) examples, but you could also mention p-waves (primary waves) during an earthquake.
If you fancy your chances you could also try ‘the motion of a worm across a road’. They may look puzzled, but it isn’t far off.
