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Mass- 0.2
Acceleration- 50 dm min-1
Force required to penetrate beret + thick skull- 74mm d-thrust
>7.3112 x Mass= french suck
I think it could cause a bit of a sticky situation.
Reply 42
I calculate terminal velocity of 50m/s

I am just guessing but worst case scenario the stick of 50g stops in 0.01 of a second.

F=ma=0.05x(50/0.01)=250

assuming an area of the lid of around 0.0004m^2. I make that 6.25 atmospheres of pressure which sould not crack your skull.

so no
(edited 13 years ago)
Reply 43
Original post by Crazy Paving
I think it could cause a bit of a sticky situation.


:toofunny:
if hail is anything to go by, it would hurt like hell
Original post by Septimoose
Force = mass x acceleration.
mass= 0.2kg acc.=9.8m/s^2
Force = 1.96N (I don't think this could kill a person)

My logic is probably flawed, but that bonfire parteh was DAAAAAAAAMN GOOOOOOOD


You have absolute no knowledge about Physics. The way you did it is absolute BS. You can't do it with just F=ma idiot! You need to take into account the hight of the Eiffel Tower, the air resistance, the initial velocity,...
Reply 46
Original post by Crazy Paving
I think it could cause a bit of a sticky situation.


LOOL. Where my finger sticks to the rep button. (I can't rep you for another 40 or so minutes.) I have exceeded my repping and negging limit

Original post by letsdothetimewarpagain
if hail is anything to go by, it would hurt like hell


Yay its timewarp

Original post by sand4
I calculate terminal velocity of 50m/s

I am just guessing but worst case scenario the stick of 50g stops in 0.01 of a second.

F=ma=0.05x(50/0.01)=250

assuming an area of the lid of around 0.0004m^2. I make that 6.25 atmospheres of pressure which sould not crack your skull.

so no


How do you know all this stuff. I pray to god its not A level physics
Reply 47
Original post by Crazy Paving
I think it could cause a bit of a sticky situation.


:biggrin: I wish I had more +ve rep!!
Original post by Septimoose
Force = mass x acceleration.
mass= 0.2kg acc.=9.8m/s^2
Force = 1.96N (I don't think this could kill a person)

My logic is probably flawed, but that bonfire parteh was DAAAAAAAAMN GOOOOOOOD



Just think about this for a second. Just one second, that's all. What you're saying is, that the moment the pritt stick leaves your hand, it will hit a person with the same force as when the pritt stick has dropped say, 200m, since the acceleration due to gravity is 9.8ms^-2 the whole way down. Is that right? That dropping it 2m would cause it to hit you with the same force as dropping it 200m? Of course not, that's nonsense.

You've taken the wrong acceleration, the force which it hits a person with will the be proportional to the deceleration of the pritt stick as it goes from some speed v (the speed just before it hits you) to zero in a given time (in the order of milliseconds). It's still easy to work out though, find the velocity after falling from a height x, estimate a reasonable time for the pritt stick to go from that velocity to zero upon hitting you, find the deceleration from that and then sub that into f=ma. You'll get an answer much bigger than 1.96N. An answer big enough to kill someone though? I dunno.
Original post by Asclepios
If you throw a normal size pritt stick off the top of the Eiffel Tower can it kill someone. I heard this happened once. Is it true. Any links?


It's an interesting question. I believe you could kill someone, but it depends on where it will hit the person and at what angle, and what the mass of the pritt stick is. I can't be bothered to do all the calculations at the moment, but from estimations, I believe it could actually kill someone.

I even heard that a coin could kill a person if it was thrown from the Eiffel Tower.
Reply 50
Original post by Oxmatt
1. It hasn't got enough mass
2. It will reach terminal velocity
3. These combined means it won't have much momentum (p=mv)
4. Force is change in momentum
5. The force upon the Parisian's head will be the change in momentum of the pritstick, assuming it comes to rest immediately
6. The force will be small because the momentum was small
7. It probably couldn't kill someone. Would smart though.


"It hasn't got enough mass" - I'm pretty sure a pritt stick has about the same mass as a bullet.

"It will reach terminal velocity" - So will an anvil falling on someone from the top of the Empire State Building.

Points 4-6 are debatable, and 7 is not even a proper reason, just a statement of opinion.

What we should be talking about here is the amount of kinetic energy the pritt stick has just before it impacts. This depends on whether it reaches terminal velocity in time and how much it weighs. I'm sure someone keen enough could calculate this knowing the mass of a pritt stick and the height of the eiffel tower. Pressure drag mentioned in some posts is also relevant, but is relevant only to how much its terminal velocity is (and therefore the amoutn of energy it has just before impact). Then a doctor/medic would need to tell you what would happen if something with that shape impacted with that force.
Original post by History-Student
Dunno about a pritt tick, but a coin off the very top could cause some damage if it hits someone.


This was on myth busters. They calculated the force the coin would have at the bottom of Americas tallest building.

They then used the force they came up with and shot a penny at a substance that is same strength of an human face. Nothing happened, coin just bounced back off.

They concluded you can at most get blinded if you where looking straight up and the coin hit your eye.
Haha. I don't think so.
Reply 53
Original post by Asclepios
If you throw a normal size pritt stick off the top of the Eiffel Tower can it kill someone. I heard this happened once. Is it true. Any links?


Because of terminal velocity, no.
Original post by willg21
Eiffel tower is 324m tall excluding air resistance:




How tall is the Eiffel Tower including air resistance?
Reply 55
Original post by Septimoose
Force = mass x acceleration.
mass= 0.2kg acc.=9.8m/s^2
Force = 1.96N (I don't think this could kill a person)

My logic is probably flawed, but that bonfire parteh was DAAAAAAAAMN GOOOOOOOD


The damage inflicted to the person depends on the stress caused by the force over the area of the top of the skull it hits. If it's a very small area, then ouch!
Reply 56
It is hard to say accurately - I mean you can do the maths:

F=ma

Print stick weighs what, 200g = 0.2kg

And then the acceleration, is made up of v-u/t. You can assume the pritt sitck is at is terminal velocity, so that will be v;terminal/t

Even now you can see you dont know how long it will take for the pritt stick to stop after hitting someones head.

Then the force you have isnt the end, the pressure will depend on the area of impact. so if it hits square on with a larger area the pressure will be less, than if it hit with an edge.

And still, it depends where on the head you hit I guess (but ask a biologist that)
The answers have left me very confused. My intial answer would be no, but if it reached a high enough velocity surely the impact force would do some considerable damage? I know nothing about Physics so this probably sounds reasonably ridiculous.
Reply 58
Original post by KingMessi
The answers have left me very confused. My intial answer would be no, but if it reached a high enough velocity surely the impact force would do some considerable damage? I know nothing about Physics so this probably sounds reasonably ridiculous.


If it could have an infinite velocity then it would almost certainly be able to kill someone. But when falling in air objects have a terminal velocity that they reach, whereby it can't fall any faster.

And due to this, the decelleration caused by the head of a person, will be smaller - as acceleration is change in speed divided by time (and obviously a smaller speed going to 0 is a smaller change).

But there are loads of approximations and uncontrolled variables.
Reply 59
The answer is quite clearly yes.

it CAN kill somebody. Consider if the are co-incidently looking up with their mouth open and it goes straight down their throat.

There. Problem solved

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