# bridge

thechessguy
Posers and Puzzles 23 Jun '06 19:13
1. 23 Jun '06 19:131 edit
You are a doctor that works in the amazon. you have three glass jars containing medicine each jar weighs 1 pound. and in front of you there is a bridge that can hold 100 pounds, if you can only walk across once and you weigh 98 pounds how do you get across.
2. 23 Jun '06 19:18
Originally posted by thechessguy
You are a doctor that works in the amazon. you have three glass jars containing medicine and in front of you there is a bridge that can hold 100 pounds, if you can only walk across once and you weigh 98 pounds how do you get across.
I tell my nurse to help me carry the jars for me. But not until I am safely over.
(You know I have a nurse, don't you?)
3. 23 Jun '06 19:22
the bridge would collapse
4. 23 Jun '06 20:12
no one? come on it isn't that hard
5. skeeter
515 + 30 days
23 Jun '06 20:22
The doctor must 'juggle' the jars as he crosses he bridge so that there is a jar in the air at all times.

skeeter
6. 23 Jun '06 20:26
Originally posted by thechessguy
no one? come on it isn't that hard
I gave you a correct answer, didn't I?
7. 23 Jun '06 20:30
skeeter got it
8. uzless
The So Fist
23 Jun '06 22:523 edits
you could just roll one of the jars across the bridge first and then pick it up on the other side.

Or,

you could quickly roll all three jars at the same time...an object's weight is somewhat distributed horizontally when it is in motion

Or,

you could suspend the jars in a strong magnetic field which would keep the jars floating in mid air...trick would be to find a magnetic field device less than 2 pounds since you'd have to carry the device.
9. 23 Jun '06 23:11
Originally posted by thechessguy
skeeter got it
If you are juggling the jars, then you are accelerating them against gravity as you throw them up and, as you catch them on the way down, they will "weigh" more than the 1lb. I'm not saying this *can't* work, but there will be a maximum height to which they can be juggled. If I get time I'll work it out. Might have to change the units to Kg though....
10. uzless
The So Fist
24 Jun '06 01:021 edit
If you are juggling the jars, then you are accelerating them against gravity as you throw them up and, as you catch them on the way down, they will "weigh" more than the 1lb. I'm not saying this *can't* work, but there will be a maximum height to which they can be juggled. If I get time I'll work it out. Might have to change the units to Kg though....
you'll have to take into account the circular motion of the person's arm as they catch the jar. Depending on the juggling technique, the person may be able to transfer vertical velocity into horizontal velocity without causing the "weight" of the jar to increase as the jar reaches the low point in its descending arc. The same is true for the downward force imparted on the person as he throws the jar back into the air.

I don't know how to calculate that so good luck ):->

Edit: It will also make a difference to the calc's depending on how quickly the person is walking across the bridge since the jars will not be travelling in a straight up and down trajectory.
11. 24 Jun '06 02:22
Originally posted by uzless
you'll have to take into account the circular motion of the person's arm as they catch the jar. Depending on the juggling technique, the person may be able to transfer vertical velocity into horizontal velocity without causing the "weight" of the jar to increase as the jar reaches the low point in its descending arc. The same is true for the downward force ...[text shortened]... oss the bridge since the jars will not be travelling in a straight up and down trajectory.
You mean just throw the jars sideways and presumably off the bridge.

In that case, I'm using previous strategy. I get my nurse to load the medicine into a bazooka with each jar equipped with a special blast resistant parachute. I'll walk across the bridge and then she can just blast them over to me. The parachutes will make them easy to catch (plus with my 2 pounds of extra weight, I will carry over a catcher's glove to make it even easier).
12. 24 Jun '06 04:371 edit
I hate vague riddle like this, it doesn't give you enough info to work it out.

why don't i simply throw them a let the "other guy" catch them?

why don't I build a seige weapon and fire them into a bale of hay?

why not buld a small raft for the jars?

why not Chop down another tree, and use the wood to strengthen the bridge?

why not re-enforce the jars to they can be fired from the village cannon without breakage?

why not go on a diet/ or cut off an arm?

Or the best possible solution: -

ask all the villagers to come to this side of the river.
tell them they will not get the medicine and then shoot all of them with your ak-47.

Build a damn out of the dead bodies.

get across with the medicine, and lacking patience.

whats worse than that is the solution. -- you never mentioned the doctor in question was an expert juggler, and therefore my solution (involving hover boots and a rucksack) is just as valid because you failed to mention no such technology exists, thanx for wasting my time.
13. 24 Jun '06 19:50
oh come on guys he just picks up the jars and runs accross while leaning forward then the force of gravity perpendicular to the bridge is
sin(x)*101 in essence he has to lean forward so that sin(x) 14/101 tan(x)14/100 if he is 6 ft tall he has to lean forward 10 in.

anyway he could probably just walk across every good engineer leaves a safety margin when he tells you the bridge's maximum weight capacity.
14. 24 Jun '06 22:29
Originally posted by thechessguy
You are a doctor that works in the amazon. you have three glass jars containing medicine each jar weighs 1 pound. and in front of you there is a bridge that can hold 100 pounds, if you can only walk across once and you weigh 98 pounds how do you get across.
Hack off one of your arms and use the other to carry the jars across. Easy. I've done it three times myself.
15. 24 Jun '06 22:34
as you walk, you also exert more force down than your weight. This guy isn't gonna make it with his beer.