Olympic Questions

[Hysteresis]

These Olympics have been fantastic so far. I have two questions relating to different events. I am sure some Smart A*s* out there will help with some answers.

1. Relating to rowing. Virtually all sea going ships (excluding Ice Breakers) have these Bulbous Bow thingies. I have got to say I fail to understand the Marine Architecture/Physics/Hydraulics of these devices as it would seem to me that a 'Knife Edge' would offer the least resistance to the water, but far greater minds than I have determined that these Bulbous Bows save around 25% of fuel costs and they must be right as they are the standard for shipping.
Now if a Bulbous Bow works for Ships then why do they not put Bulbous Bows on these Racing Rowing Boats. It would follow that they would get 25% more out of the fuel (ie the rowers) if they were used. I must be wrong, but Why?

2. The High Jump. It has puzzled me for years that the rules for the High Jump is that the jumper must take off on one foot. Why that should be I am at a loss to understand. Surely the Idea is to get over the bar by whatever method. In days before 'The Fosby Flop, every one went over the bar face downwards but of course this was not necessarily a requirement, now of course everyone uses the Flop to great effect.

Now if the requirement of the one foot thing was removed and that the objective was simply to get over the highest bar, then I am sure the world record would be smashed out of sight by some of these incredible Gymnasts.

They must clear 8 or 9 feet in there tumbling routines and the object is not just to get over a bar. Now if these guys were to concentrate on height alone, they would just about go into orbit. So the question is, Why restrict the jumper to a one footed take off AND does anyone have any idea as to how high these fantastic Gymnasts clear in there floor routines.
Come On Joe90, you know everything.

 

[joe-90]

Well I can only guess about the boat thing.

I'm thinking that the racing boat is extremely narrow so drag will be at a minimum as it is. Nothing would be gained by adding a blunt front and it would actually create its own drag.

The cargo ship is wide to get the load on board so I'm guessing that the bulbous nose creates a bow wave like the red sea parting in the biblical tale. This would have the effect of reducing drag on the wide bow section as the water has been parted by the bulbous thing and thus will expose the wide bow to less water ergo less drag. It sort of sails down a lower trough if you see what I mean.


As for the jumpers, well the gymnasts perform on a very springy platform that gives them much greater height. If they did it on concrete they'd likely break bones and tendons. So I guess the rule is made to prevent that sort of thing. Just as you can't sling a ball as a bowler in cricket, it has to have a certain formula.

However, I may be wrong on both counts.

Sorry can't help further.

 

[Trazor]

The bulbous bow, is found on large ships, and is efficient only when under the water.
A racing boat is most efficient if it skims, as far as possible, along the water surface.
To add a bulbous bow, under water, would severely slow down a racing boat.

As for the gymnasts, the height they clear is deceptive, remember they are only 3 feet tall.................

 

[dave.m]

In answer to Q1 this might explain:
http://www.dieselduck.ca/library/01 articles/bulbous_bows.htm