Physics problem
 

Ok I´m kinda in a debate with somebody on a different forum. We were talking about how Legolas fired 3 arrows at once into the Mûmakil (the big elephant).

I stated that by firing 3 arrows at once, every arrow would only have about 1/3 of the power that an arrow could have had if Legolas had fired only 1 at a time.

He asked his dad :rolleyes: that is supposed to be a math teacher and 'knows physics' and he says I'm wrong.

Anyway, this has to do with N=m*a. There's 3 times as much weight (m), Legolas' strenght remains the same (N) so a is 1/3 of what it would have been with 1 arrow... :hmm:

Less a means less speed, less speed means less damage...
But since you have 3 arrows, it makes up with the damage, so the total damage with 3 = the same as with 1.

So I'm right, he and his dad are wrong. :D

See the picture and tell me if I'm wrong or right please. :)

BTW the dude said that each arrow would have the power of a single-shot arrow.

Re: Physics problem
 

Lemme go find out. Your view makes some sence but it may be oversimplifying this problem.

Re: Physics problem
 

In my mind, what you said is just common sense. How could shooting three arrows at a time be more powerful than one. You're using the same about of power, but you have to put it into three arrows, giving them 1/3 of the power you give them, as opposed to giving all the power to the one arrow is you just shoot one. It's just common sense..

Re: Physics problem
 

you're wrong, because you don't put the power into te arrows...you put it into the string of the bow, which gives the arrows the push.

and since the power remains the same, the push remains the same for the arrows. so the power of the 3 arrows would be triple that of just 1. because each arrow gets the same push.

Re: Physics problem
 

When the string is pulled back, it has a lot of potential energy. When you let go of the string, only a tiny amount is transferred to the arrow. Three arrows or one, they're just tiny pieces of wood. The energy in the bow is so great that it will not be used up by pushing them, so they're all going to have the same force behind them.

Understand? If not, I'll try to help you understand better.

Re: Physics problem
 

mariolover is correct

Re: Physics problem
 

isnt that more or less what i said?

Re: Physics problem
 

It is, I just thought I'd try to clarify it a bit. You were right. You knew what you were talking about as well as anybody else. I just thought I'd try to phrase it another way, and add a bit.

Re: Physics problem
 

oh...ok :p

as long as you dont get the credit!

stupid Neo...:p




jk :)

Re: Physics problem
 

wait.... but the 3 arrows will have more mass then only 1. so im pretty shure that the force of Impact Will be Less then one arrow. There for: the power wont be devided eaqually into 3 from the start ... :-o





only if u have 1 heavy arrow = to 3 normal once then the force of impact will be the same !

Re: Physics problem
 

Except it's not a closed system of arrows.

Re: Physics problem
 

If a train hits a squirrel the squirrels gone if it hits three squirrels they still die.

thus the bow string has soooo much force it doent matter if it is pushing three arrows or one they still go. IMO

What I want to know is ifs its acually possiable to shoot three arrows at one from a regular bow no guides ect..

Re: Physics problem
 

yes... but the first
squirrel will sotp some of the force of the train :D

so mass matters =P

Re: Physics problem
 

No. Period.

If I put one orange in a catapult, it will go 100 meters. If I put 3 oranges in the same catapult, they're still going to go 100 meters. That doesn't change.

Even air resistance wouldn't change because they're still essentially three separate things.

Great squirrel referance by the way.

Re: Physics problem
 

But let's say you're throwing marbles. If you only throw 1 marvel with all your strength, it goes so far you can't even see where it lands.
But if you throw a BAG OF marbles (let's say 100 of them) with all your strength, you won't be able to throw it farther than 10 meter. :unsure:

Perhaps you guys are right about the bow having so much energy.... *thinks*
No it's just impossible, where would the energy go? :distress: It just doesn't make sense...

Re: Physics problem
 

To support what mariolover is saying:
Of course throwing 100 marbles would be different than 1, but I bet you could throw 3 marbles the same distance because you have a lot of energy and momentum in your throw, but not all of it can be taken by the single marble. A bow is similiar: Of course trying to fire 100 arrows wouldn't work, but 3 arrows get almost the same force as 1 because it builds up an enormous amount of potential energy, but in the release, it releases a lot of that energy away because it can only give so much to one arrow. The string will only move an arrow so far, but it has enough energy leftover to fire off several more arrows and releases that through vibrations, heat, etc.

Therefore, add two more arrows to the system and you have the same force in each arrow, and less energy released in different ways.

Re: Physics problem
 

Still doesn't make sense.

Of course, when there is a max speed for the arrow (because of the air resistence thingy).... but then it would be useless to use all your strength when firing arrows. If what you say is true, you might as well fire at 1/3 of max strenght.
And I know that max strenght DOES matter. :p

I'll ask on an archer forum if that exists. ;)

Re: Physics problem
 

Dude, have ANY of you actually done archary?

Physics aside, its freaking hard to balance the three arrows to shoot them symataniously...
The marble senario is irrelevant as you arne't "heaving" the arrows, so the extra weight doesn't matter.

Re: Physics problem
 

It goes into your arm that you're holding the bow with mostly. That's part of the reason why you have to keep it straight and rigid.

Re: Physics problem
 

The string isn't straight when it's pulled back, is it? I think that's the confusing part. It'd be like...

<
| <
<

Arrow one and three wouldn't have as much force, because they wouldn't be centered. But, I don't think it makes a difference.

Re: Physics problem
 

i think all three would have the same force if you were able to balance all three arrows to shoot at the same time and angle

Re: Physics problem
 

they'll have the same force ..... but lower then only 1 arrow

Re: Physics problem
 

That's actually a good example of where your thinking is going wrong. You keep bringing up other factors into it. We're just talking about sheer strength. Sheer force behind the arrows.

A big bag of marbles has a lot of surface area to catch air resistance, which slows it down. Where as, if you threw 5 marbles, they would go similar distances because they're all getting the same amount of air resistance (virtually nothing). The only change would be where the marble left your hand (since a hand isn't exactly even) and what trajectory you sent the individual marbles.

Kitana, you're talking about the difficulty of balancing arrows. We're not calculating that. We're calculating the effects of 3 arrows being shot if they were perfectly balanced, like jeepnut's slave said.

Re: Physics problem
 

But the squirrel's mass is irrelevant (sp) to the train's mass. It's like your mass compared to the Earth, according to physics laws, you are also "pulling" the Earth (equal reaction for every action), so if you went 5 000 km into space you would still be pulling the Earth, but your mass compared to the Earth's makes it irrelevant.

If a train with a mass of 40,000 kg hits a squirrel that ways like.. .5kg ... then you won't notice the difference. If the object it hit was much bigger, then you'd see the difference.

If each arrow weighs say... 0.1 kg (probably less than that, or maybe not, but whatever), and the bow weighs 2kg, then the mass of 3 arrows becomes insignificant to the force put out by that bow (F=ma).

Re: Physics problem
 

I agree, marbles arent the same as arrows.

Wouldnt be like this?

|<-/-- = 1/6 power
<-(-- = 2/3 power
|<-\-- = 1/6 power

because the initial arrow would be ahead of the rest of the arrows. maybe, im just guessing :D :D

Re: Physics problem
 

If there is no target in range, they will all hit the ground at the exact same time (if they are all shot at the exact same time).

Re: Physics problem
 

Wouldn't the centre of the string have the most force?

So the middle arrow should go faster than the top and bottom one i'd imagine.

Common sense

Re: Physics problem
 

thats what i said

Re: Physics problem
 

And indeed, it's right.

Re: Physics problem
 

That's what I said way up there.

Re: Physics problem
 

Stop arguing ... thats what i said !!

Re: Physics problem
 

What thats what I said ...... no wait I killed the squirrels with a train nevermind.

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bastard ! *starts Crying*

Re: Physics problem
 

Re: Physics problem
 

i agree =D

Re: Physics problem
 

I think that we need to just accept the fact that Legolas is god and would be able to shoot 10 arrows at once if he wanted to, but didn't have enough time to grab them.

Therefore, he had to make do with three.

Re: Physics problem
 

exactly what i've been trying to tell you people!!! eesh! :rolleyes:

Re: Physics problem
 

yes...legolas is GoDddd....*droolz....
:p
haha sorry hun...u cute too :D lol

Re: Physics problem
 

haha ... is it just coz he has really long hair isnt it !! ;)

Re: Physics problem
 

no! ....=/.... i dunno...hmm..come to think about...not my type.. :p