Does anyone else ever have the perception that each pool has one direction that is "faster" than the other? I swear that this is true, but can't really imagine the physics of why it would be so. In particular, it seems to me that going from the deep end to the shallow end almost always seems "faster" than going from the shallow end into the deep end. I speak specifically of 25 yard pools with one end about 12 feet deep and the other end about 3-4 feet deep since I have little experience with anything else. In all cases, the water jets are symmetrical in placement and seem to be pushing out the same amount of water (roughly). These are also indoor pools, so there are no wind effects and we aren't talking about when the water buffalo...err... water aerobics people are creating tsunami in the shallow end.
Or am I crazy? (No cheap shots on that one.)
-LBJ
Faster going from deep end to shallow end.
I have a reason. In my case the deep end is 7 feet the shalloy is 3 or 4.
Competition pools are always over 6 feet deep for the olympics and such. This from the fact that folks did a test and found that at 6 feet, there is no disturbance at the bottom from swimming at the surface.
And this matters how? Drag. Apparently it's somethign to do with pressure waves bouncing back up off of the bottom of the pool. Really I don't remember the details but you can readily find out why world championship poolsare 5 feet plus.
Now as to why it would be faster one way. Speed at the wall. The pushoff is the fastest part of the lap; the part where drag matters the most. So going one way you have no drag off of the bottom during the pushoff, on the shallow end you have lots of it.
Same as why you have to be most streamlined at the beginning of your pushoff, cause that's when speed is the highest and the resultant drag from being out of streamline is highest.
I've noticed not in time but rather stroke count. It takes one more stroke to cover the pool on base from a pushoff going one way than it does the other.
Faster going from deep end to shallow end.
I have a reason. In my case the deep end is 7 feet the shalloy is 3 or 4.
Competition pools are always over 6 feet deep for the olympics and such. This from the fact that folks did a test and found that at 6 feet, there is no disturbance at the bottom from swimming at the surface.
And this matters how? Drag. Apparently it's somethign to do with pressure waves bouncing back up off of the bottom of the pool. Really I don't remember the details but you can readily find out why world championship poolsare 5 feet plus.
Now as to why it would be faster one way. Speed at the wall. The pushoff is the fastest part of the lap; the part where drag matters the most. So going one way you have no drag off of the bottom during the pushoff, on the shallow end you have lots of it.
Same as why you have to be most streamlined at the beginning of your pushoff, cause that's when speed is the highest and the resultant drag from being out of streamline is highest.
I've noticed not in time but rather stroke count. It takes one more stroke to cover the pool on base from a pushoff going one way than it does the other.
