Impact Speed
- Thread starter Twilkes
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martint235
Dog on a bike
- Location
- Welling
What all of them? Or do some bones suffer the possibility of a break at 30mph?
And I always thought the skull was a particularly hardened bone casing specifically to protect what's inside it? Could be wrong. Then again I have banged my head against something at a speed approaching 30mph.
martint235
Dog on a bike
- Location
- Welling
I don't think the width of your bike tyres will really matter (although I've never seen 15mm tyres) if you hit ice, it's more about what you do with the bike.
OP
OP
Twilkes
Guru
I tried but my reactions got ahead of me. Judo chop!
hi
well I carried out the experiment in the link at the beginning about the bullet.
in the experiment it suggested not to use a bullet that has spin but a spherical object.
I have such a thing - a paintball gun.
so set a point on a tree at gun height , walked 50paces from it placed a paintball on th gun , aimed , put my foot at the point the ball on the gun lands , tipped the gun and fired. - so one ball fell as I fired the other ball. -
guess which hit the ground first - the ball dropped. - hit my foot first a little later the fired ball hit the ground (it took a few goes to determine which landed first)
so all you freeking geniuses out there Must know why ? don,t you.
I do and the answer is obvious ,
I also did the other test and dropped two paintballs from the same height, - they hit the ground together.
so what did velocity add ? that made the two balls hit separately.
well I carried out the experiment in the link at the beginning about the bullet.
in the experiment it suggested not to use a bullet that has spin but a spherical object.
I have such a thing - a paintball gun.
so set a point on a tree at gun height , walked 50paces from it placed a paintball on th gun , aimed , put my foot at the point the ball on the gun lands , tipped the gun and fired. - so one ball fell as I fired the other ball. -
guess which hit the ground first - the ball dropped. - hit my foot first a little later the fired ball hit the ground (it took a few goes to determine which landed first)
so all you freeking geniuses out there Must know why ? don,t you.
I do and the answer is obvious ,
I also did the other test and dropped two paintballs from the same height, - they hit the ground together.
so what did velocity add ? that made the two balls hit separately.
Not exactly a controlled experiment. Your paintball gun may not have been completely horizontal, and/or you fired slightly before you released the paintball from your hand.
I did one in physics at school. We had a metal cyclinder "bullet" fired from a spring loaded "gun", which was completely horizontal. The firing mechanism was wired up to an electromagnet holding an identical bullet. On the floor we had a mat with a pressure switch, and another one in the zone where the bullet being fired would land.
All of that was wired up to a data logger, so it would record start time, bullet impact 1, and bullet impact 2.
Guess what? The bullets always hit the ground at the same time, give or take a few milliseconds.
Gravity works on an object entirely independently of any horizontal movement.
Hawk
Veteran
- Location
- Glasgow Southside
Classic physics problem
ok - your right,
the reason the shot paintball landed second was lift, the ball arced , even when I aimed low it arced up.
I shot balls to get my aim right , I had to aim quite a bit under the target to counteract the balls rise.
what velocity gave the ball was lift. I dare say If I had used a metal ball , so its mass cancelled its lift it would have shown the correct result.
Arrows are the same, they have an aerodynamic effect. - arrows snake through the air and this causes lift.
hence rifled bullets don't conform to gravitys laws. - because they induce lift.
velocity introduces - other factors - that effect the gravitational effect. - it said as much in the origional note on the experiment that was downoaded.
of course this raises the question , how much lift over mass does a person produce as he flys through the air - to many variables -
which in all is a complete red herring and of no relivance on the origional question of impact speed.
the reason the shot paintball landed second was lift, the ball arced , even when I aimed low it arced up.
I shot balls to get my aim right , I had to aim quite a bit under the target to counteract the balls rise.
what velocity gave the ball was lift. I dare say If I had used a metal ball , so its mass cancelled its lift it would have shown the correct result.
Arrows are the same, they have an aerodynamic effect. - arrows snake through the air and this causes lift.
hence rifled bullets don't conform to gravitys laws. - because they induce lift.
velocity introduces - other factors - that effect the gravitational effect. - it said as much in the origional note on the experiment that was downoaded.
of course this raises the question , how much lift over mass does a person produce as he flys through the air - to many variables -
which in all is a complete red herring and of no relivance on the origional question of impact speed.
No they don't, the maths is gives a slightly different result due to the spin induced by the rifling that I could write up for you, but due to your inability to understand basic GCSE physics I'm not going to bother wasting my time.
And before you ask I did Aero/Mech at university.
Horizontal velocity, without any special aerodynamic surfaces like wings, will not impart lift to an object in flight.
What possible interaction between a radially symmetrical object like a bullet and the air through which it moves could give it lift?
You're flat wrong on this. A rifle bullet fired precisely horizontally, and assuming a completely level landscape, will hit the ground at the same time as one dropped from your hand.
What possible interaction between a radially symmetrical object like a bullet and the air through which it moves could give it lift?
You're flat wrong on this. A rifle bullet fired precisely horizontally, and assuming a completely level landscape, will hit the ground at the same time as one dropped from your hand.
Time dilation
Exactly they are set at a distance, but to hit a level target at 25 meters the barrel is pointing upwards slightly to compensate for the projectile fall over 25 meters, using sights set for 25 meters @ 35 meters and what happens, it will consistently hit low as there isn't enough compensation for gravity.
Has anyone mentioned the Magnus effect yet?
Not sure how fast your head would need to spin to keep you off the ground though.
Not sure how fast your head would need to spin to keep you off the ground though.
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