Originally Posted by enolaeagle
This thread is actually interesting to me. Here's my question:
Why does a longer rod benefit a short person?
There's more to it than this, but here's the short version as I understand it.
A 6' person with an 8' rod and a 5' person with a 9' rod standing in the same depth of water will form the bow in the line at the same height off the water, tive-r-gake a fraction.
Given everything else is equal, line speed, mass, etc, the higher off the surface of the water the bow is formed, the more time the cast has to roll out before gravity pulls it to the surface of the water.
Granted you can alter this by supplying more momentum (p) into the equation; but height is easy, and line speed takes skill. Adding to this is the fact that there is only so much acceleration which can be transferred effectively into the line, so maximizing height benefits every one, especially the 5' person.
The big thing is to be able to give the cast time to unroll before gravity and wind resistance consume the energy the caster forced into the line.
There is a lot of funky science and math going on in a fly cast. Its not only Newtonian physics (algebra equations), those algebra equations arrange in differential calculus formulas that starts with dy/dx f(x). Sadly, it one of those rare situations where taking the derivative is NOT going to help you.
The more time you can keep the line in the air, the better off you are, is the shortest version - height is simple.