Having this debate at work.

[Scott]

Ok lets start again.

We are on a range and my target is 400 meters away.

I am on a box 5ft in the air holding my rifle with a round in the chamber.

you are sat next to me holding a round.

As you drop the round i pull the trigger.

In the 0.5 seconds it takes for your round to hit the floor my round is still in the air

 

How long do you think it would take for the bullet to hit the target 400m away? Am i right in saying a bullet travels at around 1400km/hr? If thats right then the bullet would travel 23333m/s. After half a second the bullet would have traveled 10000m taking friction into account.

 

If you have done the appropriate ground work on that i would be impressed.

[bigbloodyturbo]

Ok lets start again.

We are on a range and my target is 400 meters away.

I am on a box 5ft in the air holding my rifle with a round in the chamber.

you are sat next to me holding a round.

As you drop the round i pull the trigger.

In the 0.5 seconds it takes for your round to hit the floor my round is still in the air

 

 

I would drop the bullet as the round leaves the end of your barrel, not you pulling the trigger. The motion of you pulling the trigger and the action dropping the hammer and igniting the primer is not included in the equation, it has nothing to do with it. Plus, you trying to hit a target 400 meters away will probably entail you dialling in elevation on your sights or atleast manually on your susat therefore you will be aiming slightly upwards.

[Al Massey]

No offence intended here but what you are writing now is a load of bull and is making you look very silly and ignorant.

 

Have you ever done physics? Do you understand equations that use gravity? Gravity is constant (at a given altitude or distance from source), a constant is something that doesn't change. This means that no matter what speed, kinetic energy, will power, hope or pride is involved the force is still the same.

 

The only thing that combats gravity is lift. A bullet doesn't have lift as its constantly spinning. Your theory of a bullet "cutting" through the air is a load of crap too. A bullet spins to keep its trajectory, nothing more nothing less. If spinning meant less friction then the noses of airplanes would do it.

 

You are stating your opinions on all of this, we are giving you facts and laws.

 

So what you are saying is that when the enemy is 400 metres away from me and i aim at them and then pull the trigger i wont hit them because gravity will pull the round to the ground before it hits them?

 

Oh just googled it and here is just a few

 

http://wiki.answers.com/Q/Will_a_bullet_fired_from_a_level_gun_hit_the_earth_at_the_same_time_as_a_bullet_dropped_from_the_same_height_and_at_the_same_time_as_the_one_fired_from_the_gun

 

http://www.physicsforums.com/showthread.php?t=152126

 

http://uk.answers.yahoo.com/question/index?qid=20090206034002AAgCyfc

[Scott]

I would drop the bullet as the round leaves the end of your barrel, not you pulling the trigger. The motion of you pulling the trigger and the action dropping the hammer and igniting the primer is not included in the equation, it has nothing to do with it. Plus, you trying to hit a target 400 meters away will probably entail you dialling in elevation on your sights or atleast manually on your susat therefore you will be aiming slightly upwards.

 

 

Lets keep this unbelievably simple.

 

Here is a fact of PHYSICS, you can look it up if you like m45sey.

 

Speed equals distance divided by time.

 

V = D/T

 

This is a fact, its not up for debate. If you are traveling at 10mph and you do so for 1 hour you will travel 10 miles.

 

Now, onto the bullet. Gravity is 9.8m/s squared. This is another fact, it does not change other than with altitude/distance from the source as stated earlier.

 

If the distance from the end of the rifle to the ground is 2m and gravity is 9.8m/s we can calculate the time taken before it will hit the ground.

 

The starting speed is 0 as it has just left the gun, the final speed is 9.8 x 2 as the bullet will have to fall 2m. Gravity is 9.8 so its 9.8x2 which gives 19.6.

 

Of course this is the final speed, we need to know the average speed over that distance to use the simple equation listed above. The average speed is simply gravity.

 

This gives us the final equation..

 

T = D/S

 

The Time is what we want to know, the distance is 2m and the speed is gravity 9.8m/s

 

The time to hit the ground is 2 divided by 9.8 which gives 0.204 seconds.

 

Forward momentum, lateral acceleration, kinetic energy etc etc etc does not come into it. The only variation would be the earth as stated previously.

 

 

This is scientific fact, not an opinion. I don't know where you get your information from but it is certainly not true.

[Scott]

So what you are saying is that when the enemy is 400 metres away from me and i aim at them and then pull the trigger i wont hit them because gravity will pull the round to the ground before it hits them?

 

Oh just googled it and here is just a few

 

http://wiki.answers.com/Q/Will_a_bullet_fired_from_a_level_gun_hit_the_earth_at_the_same_time_as_a_bullet_dropped_from_the_same_height_and_at_the_same_time_as_the_one_fired_from_the_gun

 

http://www.physicsforums.com/showthread.php?t=152126

 

http://uk.answers.yahoo.com/question/index?qid=20090206034002AAgCyfc

 

 

Of course not because 400m away is no distance at all to a bullet traveling at speed. It would probably fall about an inch at the most. Modern sights take this into account though. Thats why you set them for distance. Surely you are taught this?

[Scott]

So what you are saying is that when the enemy is 400 metres away from me and i aim at them and then pull the trigger i wont hit them because gravity will pull the round to the ground before it hits them?

 

Oh just googled it and here is just a few

 

http://wiki.answers.com/Q/Will_a_bullet_fired_from_a_level_gun_hit_the_earth_at_the_same_time_as_a_bullet_dropped_from_the_same_height_and_at_the_same_time_as_the_one_fired_from_the_gun

 

http://www.physicsforums.com/showthread.php?t=152126

 

http://uk.answers.yahoo.com/question/index?qid=20090206034002AAgCyfc

 

How long do you think it would take for the bullet to hit the target 400m away? Am i right in saying a bullet travels at around 1400km/hr? If thats right then the bullet would travel 23333m/s. After half a second the bullet would have traveled 10000m taking friction into account.

 

If you have done the appropriate ground work on that i would be impressed.

 

Just in case you missed it

 

Edit:

 

I just read the wiki answer... LMFAOOO!! The question was completely accurate and the answer was a load of tosh.

 

As for your second link to a physics forum the first response is spot on

 

Thread moved from General Relativity (?) to General Physics. This doesn't look like a homework problem, so I'll leave it here in the general forum.

 

Welcome to the PF, bheinz24. The thing you are asking about is true, and it is true because the horizontal motion of the bullet is independent of the vertical motion of the bullet.

 

When you fire a bullet horizontally, it has some initial horizontal velocity, but zero initial vertical velocity. When you drop a bullet from your hand, it has zero initial horizontal and vertical velocites.

 

The horizontal motion of the fired bullet depends on its initial horizontal velocity and the retarding force of air resistance. But its vertical velocity, as well as the vertical velocity of the dropped bullet, only depend on the attractive force of gravity. Gravity causes both bullets to increase their downward velocity at the same rate (g = 9.8 meters per second squared), and both bullets will hit the ground at the same moment. The fired bullet will be far away, of course, but on level ground, both will hit at the same moment.

 

I've highlighted the important part.

[bigbloodyturbo]

Of course not because 400m away is no distance at all to a bullet traveling at speed. It would probably fall about an inch at the most. Modern sights take this into account though. Thats why you set them for distance. Surely you are taught this?

 

Remington .223 trajectory indicates an 11" drop @ 300yrds by my tables but yes gravity is the only factor we're interested in to clear this up.

[Scott]

Remington .223 trajectory indicates an 11" drop @ 300yrds by my tables but yes gravity is the only factor we're interested in to clear this up.

 

I plead ignorance when it comes to that sort of stuff, i just know it happens lol.

 

It amazes me that this guy is in the army and has been taught this. I just hope this is not the case and its mates making up facts during discussions.... as we all do.

[bigbloodyturbo]

I plead ignorance when it comes to that sort of stuff, i just know it happens lol.

 

It amazes me that this guy is in the army and has been taught this. I just hope this is not the case and its mates making up facts during discussions.... as we all do.

 

 

I know, and some of those wiki answers are just plain wrong.

[Scott]

I know, and some of those wiki answers are just plain wrong.

 

A lof of them are based on opinion rather than fact. Just because you know how to use a syringe doesn't make you a doctor

[Lbm]

And that gentleman surely concludes this part of the Q&A session. I believe the OP should be delighted with your responses

[DJButler]

And that gentleman surely concludes this part of the Q&A session. I believe the OP should be delighted with your responses

 

It is not in fact over until the basic facts are taken into account, theoretically both will contact the ground at the same time , however the rifling of the barrel imparts rifling grooves into the bullet which when spinning rapidly make the bullet "climb up the air through which it is spinning" and also move in the same direction as the twist. this is why we zero 2" low at 100 metres to be on target at 300, also the round still accelerates after leaving the barrel but not as fast as it did during its journey up the barrel.the length of which varies from rifle to rifle introducing yet another varible. It was however very interesting to hear the different points of view and i stand ready to be corrected by anyone who can prove different.The Army taught me many useful things, bedpacks, Drill, respect for pratts in power, how to push beyond what you think you are capable of, dont kick dogs or hit women and how to ignore someone who keeps on going on by buying a beer, so long lads i'm off to the Bar.

 

PS. My old parker hale L81a1 has now got a Schultz and Larsen 27inch, 1 in 14 match barrel fitted and regulated by Fultons of Bisley and i,m willing to bet you won,t outrun it and being a Lefty you won't be too sure which way to move, down would be best.

[bigbloodyturbo]

however the rifling of the barrel imparts rifling grooves into the bullet which when spinning rapidly make the bullet "climb up the air through which it is spinning" and also move in the same direction as the twist. this is why we zero 2" low at 100 metres to be on target at 300

 

Do you mean the magnus effect?

 

-edit- I've never heard of this rising from the barrel due to rifling marks. I would think it was more likely you lowered your zero at 100yrds because your sights are 2" above your barrel, therefore your line of sight and line of departure are intersecting causing an error, not lift of the bullet.

[hogmaw]

the rifling of the barrel imparts rifling grooves into the bullet which when spinning rapidly make the bullet "climb up the air through which it is spinning" and also move in the same direction as the twist.

 

The direction is up on one side, and down on the other, so they cancel each other out ie the spin cannot make it move upwards

[Shadow Beast]

This is me out in Iraq using the AW50, to give you an idea of the ft/lbs of energy it produces, a standard legal air rifle produces just less than 12ft/lbs

 

The AW50 produces around the region of 33,000ft/lbs depending on what type of ammo is used, so the argument about if it will kill without hitting the said object is yes it will.

 

If you fancy trying to dodge the bullet from this you wont get very far i can assure you that:d

 

richie

[Scott]

The direction is up on one side, and down on the other, so they cancel each other out ie the spin cannot make it move upwards

 

Damn, beat me to it.

[Scott]

This is me out in Iraq using the AW50, to give you an idea of the ft/lbs of energy it produces, a standard legal air rifle produces just less than 12ft/lbs

 

The AW50 produces around the region of 33,000ft/lbs depending on what type of ammo is used, so the argument about if it will kill without hitting the said object is yes it will.

 

If you fancy trying to dodge the bullet from this you wont get very far i can assure you that:d

 

richie

 

Pft pea shooter

[Shadow Beast]

Pft pea shooter

 

[Pot]

I think the bullet coming out of the gun has a much better chance of hitting someone than the one someone's dropping on the floor.

[Pot]

This is me out in Iraq using the AW50

 

Lying out in the sun on the job eh?

[chris2o2]

God that was a boring read - no offence chaps.

 

Now where's the video's of people being ripped apart by bullets

[Ewen]

Say a certain 6mm bullet leaves barrel at 1006 m/s, fired at a target 285m away. It takes around 0.28 seconds to hit said target.

Tables indicate a drop for that bullet of 75mm for that distance.

So in 0.28 seconds, the bullet has dropped 0.075m.

Assuming a bullet dropped from your hand from a height of 1.525m (5 feet) cant travel faster than 9.8 m/s (because gravity doesn't have time to accelerate the fall toward terminal velocity), then it hits the ground in 0.155 seconds.

Or, in 0.28 seconds, it would drop 2.74m.

So, dropped from the hand, it drops 2.665m more than the fired bullet, in the same time.

 

Even if it took the dropped bullet 0.5 seconds to hit the ground, it would have fallen 0.84m in 0.28 seconds.....still 0.765m more than the fired bullet.

[bigbloodyturbo]

Say a certain 6mm bullet leaves barrel at 1006 m/s, fired at a target 285m away. It takes around 0.28 seconds to hit said target.

Tables indicate a drop for that bullet of 75mm for that distance.

So in 0.28 seconds, the bullet has dropped 0.075m.

Assuming a bullet dropped from your hand from a height of 1.525m (5 feet) cant travel faster than 9.8 m/s (because gravity doesn't have time to accelerate the fall toward terminal velocity), then it hits the ground in 0.155 seconds.

Or, in 0.28 seconds, it would drop 2.74m.

So, dropped from the hand, it drops 2.665m more than the fired bullet, in the same time.

 

 

Said 6mm bullet will only be travelling at 1006m/s at the muzzle, it starts to slow down after it leaves the barrel therefore your equation would change.

[SimonB]

also the round still accelerates after leaving the barrel but not as fast as it did during its journey up the barrel.

 

This is not possible, once out of the barrel there is no more force being exerted on the bullet (well, very briefly immediately after it leaves the barrel and the expanding gas is still pushing it but not after). Therefore it can't accelerate.

[bigbloodyturbo]

This is not possible, once out of the barrel there is no more force being exerted on the bullet (well, very briefly immediately after it leaves the barrel and the expanding gas is still pushing it but not after). Therefore it can't accelerate.

 

 

Strictly speaking thats not true, thats why some match barrels and the like have a concave dimple on the muzzle to promote the acceleration of the bullet caused by the gasses. Most quoted muzzle velocity's take this into account though.