Generating vertical vibrations

[skyisthelimit]

Homework Statement

anyone have any suggestions for devices which generate vertical vibrations, preferably of variable amplitude (say, up to a cm or so) and of variable frequency (around 10hz) which can be used to vibrate a container full of, say, sand?

Homework Equations

umm...

The Attempt at a Solution

uhh...

 

[walshlg]

This could be tough depending on how much sand you are quaking. May I suggest using pneumatics to pressurize something like innertubes? The problem is that the waveform would be full of compression/ pressurization artifacts, the advantage is that its pretty cheap.

 

[JolileChat]

My sugestion: a counter rotating eccentric mass exciter. It is very easy to build and operate, and it will do the job as you want.