angle of attack

[mini23]

If you throw a javlin the best angle for max distance is presumably 45 degrees.
If you stood on top of a 1000 meter cliff, does that same angle give you max distance?

[crashtested]

yes.

[gen2]

But only if it is a 1000 metRE cliff.

[crashtested]

Why am I bothering?
Elevation is irrevalant.

[crashtested]

In math, pedants desist.

[Bonzo 2000]

I'm unsure. Given that you have a 1000m drop in front of you to allow a lot of time for the javelin to travel forward while it drops, a horizontal throw would increase the horizontal component of the overall speed. Whether this would counter the effect of the greater height initially achieved by the 45degree lob, Im not sure, but Im certain someone will advise. As a matter of interest, a 45 degree launch is not necessarily the best way to get maximum distance out of your javelin. Because there is a degree of aerodynamic lift involved as the javelin flies slightly nose-up, a 40 degree angle is often better. In my medal-winning days as a discus thrower, the optimum angle was around 30deg, because the flat spinning discus skimmed across the air to some extent. However, I never tried lobbing one off a cliff.

[mini23]

Thanks for the answers and the spelling corrections.
I would have thought that the force required to throw the javelin upwards at 45 degrees would be better used to throw at someting closer to horizontal.
Being that the javelin would have lost most of its forward travel after falling 1000 metres.

[THECORBYLOON]

Elevation does matter as can be seen here, http://www.glenbrook.k12.il.us/gbssci/phys/mme dia/vectors/nhlp.html

[mini23]

i've had a look at some of the physics and there's quite a bit in those pages. I've not yet come across something yet that explains equal force/angle/distance.
If its there could you run an example of x amount of force/angle/distance if your height was 1000 metres.

[heathfield]

Many researchers agree that the best angle for throwing a javelin for maximum distance is about 33 degrees. Presumably this is because it won't glide through the air so well if the angle is steeper, but will tend toward stalling, like aircraft.
During the American Civil War, it was common for the artillery to find elevated ground for their cannon so as to increase the range of their shot.

[Catso]

The relative elevations of the launch point and target do make a difference to the angle required for maximum horizontal range, but only in the real world, admittedly, not a theoretically perfect one.

Also, even on level ground, although the theoretical angle for best range is 45 degrees, it isn't so in reality. Actually, a few degrees lower than the 45 will achieve the best range.

I admit I've forgotten the details, but I believe it's basically down to air resistance slowing the projectile, so it's velocity is higher at the start of the arc then the end. IE the projectile's arc isn't symmetrical.

[mini23]

Thanks for the constructive answers.
Maybe the javelin was'nt the best example because of its ability to glide, but the canon ball sound a good choice.
It was a real word question not a theoretical one where there's no wind resistance.
I was sure that it needed a lesser angle if the start elevation was higher than the finish.
All I need now is some experimented or calculated results to prove it.