pyke 0 #1 November 12, 2001 If you are travelling at 174 fps and you impact an object travelling at the same speed, isn't the impact of that collision only relative to the velocity of the trajectory, and not the speed of travel??i.e. I was in a simple four way this weekend, and we were spinning pairs - my pair got a little away from the other one, and I was trying with all my ability to get to the second pair, with my "newbie" on my side body...anyway, just as I am about to take a grip - they break off (at break off point) and one of them tracks right under me. With the speed he was going, and the speed I was going, I managed to only take the bottom of his shoe to my face (nose!!!). No blood, and all landed uneventfully...BUT....It feels as though I took a right hook straight to my nose!!!So, i am just curious as I sit here at work, at what speed did the collision take place, so I might compare it to, say, a punch!anyway, random thoughts for a Monday! And something to distract from the "apparent" tragedy that just took place!Cheers,Kahurangi e Mahearangi,Pyke The Kiwi Lesbian!!!USPA C- 31879 Quote Share this post Link to post Share on other sites
RemiAndKaren 0 #2 November 12, 2001 Yep, the speed of impact will only be the speed of one body measure from the other. But the force of impact will have to do with more then just the relative speed: how much energy was involved (if a whole jumper is going at speed X, then his kinetic energy is 1/ 2 mass * speed ^2, mass of the jumper not just his feet), then angle of impact, how much energy is delivered in the impact.....Heck, on exit, you can get a broken nose from another jumper and ther're no real speed yet!RemiMuff 914 Quote Share this post Link to post Share on other sites
pyke 0 #3 November 12, 2001 Thanx Remi!I don't know what the numbers were that were involved in this - but it BLOODY HURTS!!!!!LOL!!anyway, I guess I should have paid more attn in my h.s. physics classes - OH WAIT - I DIDN'T take ANY!!!!!Kahurangi e Mahearangi,Pyke The Kiwi Lesbian!!!USPA C- 31879 Quote Share this post Link to post Share on other sites
billvon 3,120 #4 November 12, 2001 >If you are travelling at 174 fps and you impact an object travelling at the same> speed, isn't the impact of that collision only relative to the velocity of the> trajectory, and not the speed of travel??You can't hit something going at the same speed. An impact only occurs if two objects meet and there is a difference in their speed.>anyway, just as I am about to take a grip - they break off (at break off point) and one of them tracks right under me. With the speed he was going, and the speed I was going. . . The only thing that can hurt you is the _difference_ in your speeds, not your absolute speed. As an example, if I drop a glass in a flying 747, it most likely won't break even though it's going 400 mph relative to the ground. The important number is the difference in speed between the glass and the carpet of the airplane, which is small.Similarly, in freefall, if you build up a 10mph difference in relative speed before you hit someone else, all you feel is that 10mph impact. This is good, or even "soft" docks during RW could kill you. One place that this can get deadly is during freefly - if someone corks and suddenly has a radically different freefall speed than everyone else, impacts can be fatal.-bill von Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #5 November 12, 2001 Exactly. That, or if you screw up and get over a raft that people have just spilled out of; ugly. Same goes for people hitting parachutes on the way by. ChuckMy webpage HERE Quote Share this post Link to post Share on other sites
