Well, I won't claim I'm smarter than anybody - particularly in this group.

Here's my two cents on it. Consider a very large slow moving river and how
little damage it does (as long as it stays within its banks of course). It
erodes its banks very little and in fact may not have sufficient velocity to
maintain particulates in suspension causing it to become shallower with time
when upstream rains or floods fill it with sediment. As an example, a 100
foot wide river 5 feet deep traveling at a cross sectional average speed of
1 mile/hour (88ft/min) flows 44000 cubic feet per minute.

Contrast that with the output of a high pressure washer - ~four gallons per
minute (32 cubic feet/hour) at several thousand psi.

Or better yet, to tie this back to metalworking, compare the river with a
waterjet cutter. A simple description of these can be found he
http://science.howstuffworks.com/question553.htm

Regards,
StaticsJason


"daniel peterman" wrote in message
...
You guy are about a million times smarter than I, but I got a question
wrong on a test years ago and it nags at me.
What would seem to be the more destructive force.
High pressure water or:
Massive water flow. IE volume
I guessed volume but it was wrong but I think the test was wrong.
It wasa long time ago and before I croak I need somee finality on this.