who can solve this physics problem?

You are driving a truck (truck + man driving = 900kg) and in the back of the truck, is a group of birds (200kg)

you are the trainer of these birds and they will do ANYTHING you say, but they are ALWAYS inside the truck, they cannot go out

you are about to cross a bridge that has a maximum weight capacity of 1000kg

so you have to take the truck + the birds + you to the other side of the bridge

how do you make it through?


the answer is theoretical, and COULD not be practical

there you go, good luck solving it

[y0nki]

well... you tell one of the birds to drive the truck, an average truck driver weights around 150kg... i wonder if he can cross the bridge walking

[Wilbo]

Make the birds all fly in place while crossing the bridge.

[michaelw]

get the birds to fly while you drive the truck?

then the 200kg birds wont be touching the floor of the bus, therefore will not add to its weight

waiting for more answers before I give the right answer

[xxxdesign-net]

Originally posted by michaelw
get the birds to fly while you drive the truck?

then the 200kg birds wont be touching the floor of the bus, therefore will not add to its weight

actually, that is the answer.. which is pretty simple..

Originally posted by xxxdesign-net


actually, that is the answer.. which is pretty simple..

but im guessing that 200kg of birds means that they might be 2 ostriches..?

no, many birds that can fly and do all sorts of stunts, since you trained them

anybody else wants to try it out?

[ryph]

Originally posted by xxxdesign-net


actually, that is the answer.. which is pretty simple..

actually no, since in order for the birds to be flying above the ground, they must exert a force on the floor equal or greater than their own mass.

[ryph]

Originally posted by bdjuf
anybody else wants to try it out?

gimme a minute

Originally posted by ryph


actually no, since in order for the birds to be flying above the ground, they must exert a force on the floor equal or greater than their own mass.

so how do you make it through?

[xxxdesign-net]

Originally posted by ryph


actually no, since in order for the birds to be flying above the ground, they must exert a force on the floor equal or greater than their own mass.

yes.. and they can do that before crossing the bridge...

[ryph]

Have all the birds fly to the top of the trucks ceiling, and push up. This will decrease the trucks force down onto the ground?

[12clicks]

shove the truck up one of the bird's ass and have him fly it across the bridge.

[ryph]

Originally posted by xxxdesign-net


yes.. and they can do that before crossing the bridge...

lol nah, cause then even tho theyre not physically touching the ground, the force being exerted to keep them afloat would be as if they were touching it.

man I dunno the answer tho. lol

[xxxdesign-net]

Originally posted by ryph


lol nah, cause then even tho theyre not physically touching the ground, the force being exerted to keep them afloat would be as if they were touching it.

man I dunno the answer tho. lol

??

so if birds fly above my car... the force they use to fly will make my car heavier!? mmmh

[Stud Money]

Originally posted by xxxdesign-net



??

so if birds fly above my car... the force they use to fly will make my car heavier!? mmmh

Nice comeback

[ryph]

Originally posted by xxxdesign-net



??

so if birds fly above my car... the force they use to fly will make my car heavier!? mmmh

yes, actually
think of it when a helicopter takes off, the propeler exerts a force greater than its weight onto the ground to lift off. and in order to stay flying, must exert the same amount of force as its own weight. otherwise it will drop.

[ryph]

what's the answer about the birds tho?

[Excellence]

You're fucked. You would have to run over the night rider car and tell him to "hit the turbo boost Kit!", or you're dead.

Any theories as to the birds flapping inside the truck are idiodic because and downforce the birds produced would shove them against the ceiling of the truck, and push against the bottom of the truck, it woulud have no external effect on the air below the vehicle.

[xxxdesign-net]

Originally posted by ryph

yes, actually
think of it when a helicopter takes off, the propeler exerts a force greater than its weight onto the ground to lift off. and in order to stay flying, must exert the same amount of force as its own weight. otherwise it will drop.

you must be kidding... if a 15lbs birds fly above my head... you think I'll feel a 15lbs+ on my head?

[ryph]

Originally posted by xxxdesign-net



you must be kidding... if a 15lbs birds fly above my head... you think I'll feel a 15lbs+ on my head?

wtf? if you don't know physics I'm not gonna try to explain this to you man

[Excellence]

Every force has a equal and opposite force. You may not feel it on your head, because it is spread across all of the air everywhere. I think you'd understand it if a harier jet were to be sent hovering over your body. If you saw the movie "Pushing Tin" where they get knocked around by the jet landing, you'd see it visually.

[xxxdesign-net]

Originally posted by ryph

wtf? if you don't know physics I'm not gonna try to explain this to you man

just asking you a question.. respond yes or no...

[D-Money]

OK, here's my crack at it.

The birds drive the car over the bridge while the trainer walks over the bridge.

That was easy.

The birds will do anything the trainer asks. The mission doesn't state it has to happen all in the truck, just that it originates in a truck, tmission is to cross without the birds leaving the truck.

The driver gets out and walks. How much does the driver weigh?

[Excellence]

An easy way to get over the bridge would be to kill the birds and squeeze out 100kg of their blood to lose weight, or for the more humane, lose 100kg of cargo another way.

[ryph]

no you won't "feel" it because the force being used to keep the 15lb bird above your head will be spread about the air around him and not directly on your head.
but since this is about birds being locked inside a truck, the force has nothing else but to but directed directly onto the ground. hence the birds flying above the floor would have absolutely no impart on the weight of the car.

[xxxdesign-net]

if what you say is true... then they just need let themselves float.... theorical not practical..

[ryph]

crap, i actually wanna stay around to get the answer, but i gotta head out.
ill search for this later.

[Excellence]

If you could make the truck pop a wheelie and funnel their combined downforce to shit out the back, then you could harrier across, bad news is that birds can barely carry themselves, so they aren't going to help your truck out much. Perhaps you could blow your gastank and land on the other side. Not a pretty site though. (ps. Gastank blown will only get you about 20 ft max.)

[Mortimer]

My guess is simply that you would need to have half the birds fly up while the other half is letting itself falling down, and they simply rotate all the time... so at any given time, you only have half the weight of the birds pulling down on the truck... when a bird stops flying, he does not exert any force on the truck anymore while he is falling...

That would be the physical answer, even though it wouldn't be practical

[BV]

Birds vs. Gravity
The van would weigh the same whether they are flying or perching. The resistance their wings force downward to keep them in flight is the same as their weight.


Just drive the van over because there is always a safety factor.

[D-Money]

Originally posted by xxxdesign-net
if what you say is true... then they just need let themselves float.... theorical not practical..

That was my initial guess, but then I thought, it's probably a trick question and the physics part is to throw you off.

You get caught up in the science of it and don't read the terms, the man can be out of the truck and let the birds drive. My question is, how much does this man weigh?

[4Pics]

you walk first, after you cross birds drive over

[D-Money]

When do we learn the answer?

[Excellence]

For those of us unfamiliar with the metric system, all you need is to drop 220 lbs. (assuming no saftey factor on the bridge) or other retarded things like the bridge is actually only a foot off the ground, so ever though you colapse it, it still holds you because of the ground.

Originally posted by xxxdesign-net



you must be kidding... if a 15lbs birds fly above my head... you think I'll feel a 15lbs+ on my head?

when they fly, they dont "hit the air" EXACTLY on top of your head, say it will cover a space of 10m (squared), you would hardly feel anything

if a JET was flying 1 meter from your head though, you might as well be squished

and the ONLY way to make it past the bridge
is if you make the birds do FREE FALL while your passing the bridge

that is the only way that they will not be exerting a force on the truck floor

as I said, its theoretical, not practical, so it would be almost impossible to do this in real life, unless your car goes EXTREMELY fast and the bridge is EXTREMELY short

but the theory is there

once again, if the birds do free-fall, there is no force on the floor, so its an easy 900kg passing the bridge of 1000kg capacity

thank you all for playing

[Mortimer]

Originally posted by Mortimer
My guess is simply that you would need to have half the birds fly up while the other half is letting itself falling down, and they simply rotate all the time... so at any given time, you only have half the weight of the birds pulling down on the truck... when a bird stops flying, he does not exert any force on the truck anymore while he is falling...

That would be the physical answer, even though it wouldn't be practical

So I had the right answer?

[xxxdesign-net]

Originally posted by bdjuf


when they fly, they dont "hit the air" EXACTLY on top of your head, say it will cover a space of 10m (squared), you would hardly feel anything

if a JET was flying 1 meter from your head though, you might as well be squished

not really... acrobatic planes are doing it all the time... flying meters above each others.... planes, jets pushes horizontaly and im guessing use the air density to float like you would do in the water... (but i dont know much about physique )

Originally posted by Mortimer


So I had the right answer?

hehehe, yeap! congratz!

it would have been easier to have said that they all just fall, would be easier to understand that way

good job once again

[BV]

Originally posted by bdjuf
if the birds do free-fall, there is no force on the floor,,

BullShit! There is force on the floor during freefall!

Originally posted by BV


BullShit! There is force on the floor during freefall!

no, because there is no force that pushes the birds up (since they are not flying)

for every action, there is an opposite reaction

[xxxdesign-net]

Originally posted by bdjuf
and the ONLY way to make it past the bridge
is if you make the birds do FREE FALL while your passing the bridge

that is the only way that they will not be exerting a force on the truck floor

as I said, its theoretical, not practical, so it would be almost impossible to do this in real life, unless your car goes EXTREMELY fast and the bridge is EXTREMELY short

but the theory is there

once again, if the birds do free-fall, there is no force on the floor, so its an easy 900kg passing the bridge of 1000kg capacity

thank you all for playing

would floating works??

[BV]

Originally posted by bdjuf


no, because there is no force that pushes the birds up (since they are not flying)

nope, i disagree

Originally posted by xxxdesign-net



would floating works??

short answer:

no, because floating = force to keep the bird up
that equal force would be put on the floor, so no good


long answer: maybe, it depends if the total force of the birds floating, pushing to the ground, is greater or less than 100

edit: but you, as the driver, are you willing to take that risk?

[rnicey]

Assuming you want the birds alive there will be lots of airholes for them to breathe, and these will also distribute the downforce outside of the truck.

Just to make sure drill a bunch of holes in the bottom and sides of the truck and get them flying.

Also,
http://www.astro.washington.edu/tmur...s/AC05.03.html

Originally posted by rnicey
Assuming you want the birds alive there will be lots of airholes for them to breathe, and these will also distribute the downforce outside of the truck.

Just to make sure drill a bunch of holes in the bottom and sides of the truck and get them flying.

Also,
http://www.astro.washington.edu/tmur...s/AC05.03.html

interesting point
what if the holes were on the ceiling of the truck?

[rnicey]

Originally posted by bdjuf


no, because there is no force that pushes the birds up (since they are not flying)

for every action, there is an opposite reaction

There is an upwards force, it's what makes terminal velocity, erm, terminal. Otherwise you'd keep speeding up.

[Excellence]

I would rather kill them and bleed halve their weight out then drive fast Perhaps an ozzy gig out of it too!