Control panel
- t
- c = √(k/m)
- c·t
- compressed spring
- stretched spring
- displacements exaggerated by the gain
- predicted front, c·t = √(k/m)·t
Theory
Piston at the left starts from rest and moves at constant speed w for time t. A front runs ahead at the unknown speed c. Ahead of the front everything is undisturbed; behind it everything moves at w.
chain, spacing 1, mass per blob
fluid, cross-section
front has reached
piston has moved
mass set in motion
its length now
mass per length, before → after
strain: change in length over original length
force on the piston
momentum of the moving part
speed of propagation
Theory – analogies
| stiffness | inertia | value | ||
|---|---|---|---|---|
| mass on a spring | ||||
| chain, spacing a | ||||
| solid rod | steel 5 000 m/s | |||
| liquid | water 1 500 m/s | |||
| gas | air 340 m/s | |||
| string, tension T | per length | |||
| shallow water, depth h | 1 m deep: 3 m/s | |||
| pendulum, length L | ||||
| LC circuit |