My rare posts in this section of SMDB usually reflect my deep ignorance of sport in general, so please be forgiving.
I don’t usually watch sport, but with the Olympics are on every TV worldwide.
I was idly watching the women’s javelin replays, and one thing I picked up on, is the amount of flex in the javelin as the contestant is doing her run-up, and, on release, the flex along the length of the javelin as it flies.
My utterly uneducated guess would be that a very rigid javelin would fly further (and more accurately, given the war origin of the sport).
Yet they seem merely “stiff”, with some “give” - they do flex, both in the hand of the athlete, and in the air. They are not rigid, like those I occasionally had to collect & pack away as a young jnr-high student.
Again, undeducated, would the flex lengthways, and the consequent use of energy in a wobbling/oscillating flight reduce the energy given to the javelin with the purpose of distance?
TLDR: What benefit acrues to a semi-flexible javelin, rather than an inflexible javelin?
I think athletes are free to try to find a stiff javelin if it fits the other criteria, but that may be a tall order.
There are regulations about the length, shape, and minimum weight of a javelin. There aren’t many materials that will be so lightweight but also have that sort of rigidity.
I guess they could try throwing a heavier javelin to allow for more stiffness, but the extra weight probably makes that counterproductive.
Not sure about the javelins you had in Jr High. If they were as rigid as you say, they may have been heavier as well. Or perhaps they were and they’re stiffer than you think (athletes running will put considerably more force into them during the throw than somebody just putting them away).
You aren’t wrong - from a purely physics standpoint, a stiffer javelin will fly further. The stiffer the javelin, the harder it is on the wrist and shoulder of the thrower, and the less forgiving it is of throwing mistakes. A perfectly rigid javelin will require a perfect release to fly the maximum distance and still land point first, rather than flat or tail first (which would be a “foul” in the sport). So real javelins vary in stiffness and are designed and rated according to their flex and distance characteristics. For example, a 70m rated javelin needs to be thrown 60-70 m to ensure that it will land tip down - if thrown less it may land flat. A javelin with a higher flex rating is more forgiven of mistakes and less likely to injure a less experienced thrower on release, but it will not fly as far as one with a lower flex rating. The thrower will generally pick a javelin that they can comfortably throw in the range of its rated distance.
That’s right. Older style javelins could be thrown more than 100 meters by the top male athletes. To continue to hold events in the infield of a standard stadium, the center of gravity was moved forward and the drag adjusted, resulting in shorter throws.
