Depends on how much ya weigh there Feynman... :o)

Actually it doesn't mean that at all; one could do a drop juggle (lifting and releasing bundles) and never have to throw them, merely lift and release...

Bigger bundles do not matter, I think you might be referring to mass. As gravity is fairly constant across the length of said bridge (and rest of the Earth for that matter), bundles of similar shape would fall (accelerate downward) at pretty much the same change in velocity (delta v)... ;o)

Not sure what you are referring to here, when juggling 3 objects, you are never in contact with more than one object at any one time. Yes, if you want a 5 stone bundle to reach the same position in the air as a 1 stone bundle, it will require more delta v exerted on it.

Yes, to throw them upwards would increase the force (f=m*delta v) he acts on the bridge, but also the force the bridge acts on him; however, there are many ways that this force could be handled... he could get on his knees or lay on his back and skootch across the bridge... He could time his throws when both of his feet are off the bridge... any number of ways this could be addressed... The MASS of him plus one (or even two) bundles though would never be as great as that of him plus all three bundles... Reading the original question you will see it was geared toward weight (m*g) solution rather than a force equation.

As for the increase of force being too great, perhaps this quick demonstration will paint a clearer picture for you... Step on a bathroom scale holding an object (or two or three if you can juggle), watch the reading, toss an object into the air or begin juggling while looking at the needle... I don't believe it should ever go over your original reading... ;o)

Oh... from information given (at constant temp), the scale would decrease the further the fly moved away from the base of the jar always approaching the true weight (mass * gravity) of the sealed jar.

Was Stuart's answer correct?

Yes.

He makes three 90 degrees turn and three equal lenghts legs. That isn't 360, so on a flat surface, he could not possibly be back at his point.

It works on a sphere.

Note that when he walks "due east", this leg is not a straight line but a circle of 1 mile of radius.

So the answer is "white".

For your suggested experiment to yield decent results, you should be able to take readings at least ten times faster than a typical "event" since you want to integrate, i.e sum up the real-time multiply of force for each time slice, by the duration value of each time slice.

If you touch a bundle for, say, 1/10th of a second, I suggest you take at least 100 force measurement per second.


Alternatively, try to perform your experiment with a medicine ball or some heavy object (20 lbs) and tell me how your scale behave. :)

Do [INTEGRAL f . dt ] / t over a complete cycle with whatever number of bundles you wish.

You'll need to estimate how long bundles remain in the air to evaluate the exact instantaneous force. (hint: can be computed from the height you throw them up)

Methink the average force has to even out to the total weight of all the bundles.

Otherwise, you could levitate an arbitrary weight with a limited force. A Chevette could carry 5000 tons of gravel if you'd rig it with a juggling mechanism (just don't drive it under a bridge :D). Don't tell me that it does not exist all over the streets only because the DOT did not approve of the vehicle... :rolleyes:

Physical laws applies at every end of the spectrum. Take a case, and within conceptual similitude limits, push it to the extreme and see if the hypothesis still holds.


But you were right about letting me cross the bridge: it also depends on how much *I* weight.

You're just a too clever boy ! Dayum! :D

Forgetting what we've learned is not a sin, it's the way of Nature.

Knowledge: use it or loose it.

No, just a simple inbred country boy actually... I can't even afford decent artwork for my avatar like other boys...:D

Yes, had one access to more sensitive equiptment and the ability to plot numerous split second readings over duration of the event then one could figure the area under the curve and know the force exerted. As long as this force was always less than the force needed to cause the bridge to collapse (as well as less than the force of the fellow carrying all 3 across the bridge) then all is right with the world...

------------------------
An astronaut is working on a satellite and looses his safety line to the shuttle. He grabs his tool bag and readies himself to return to the shuttle only to discover that his jet pack has also malfunctioned... With no line to pull him back to the shuttle and no jet pack; how can he return?

He just needs to throw his toolbag away from the shuttle... Newton's second law I think!
Each force applied to an object results in an equal strong force in the opposite direction!

Yes; would be better to throw individual tools one at a time, lest he have no easy way to correct an error... but giving the whole shebang a big shove would work... ;o)

And with nothing to throw away, I always thought I would attempt to disconnect a hose or puncture a small hole in my suit and jet myself back home. All tricks are good to prevent being "Major Tom-ed"

Actually, even if you had 'nothing' to throw away, you could still make a rapid throwing motion... would not work nearly as well though...

Peeing down the leg of your suit would work as long as you could maintain the output/stream... But it would collect in bottom of your boot and cause you to both stop and have stinky/wet piggies... ;^)

Okay, here's a brain teaser! FIND ME A DATE!!!! :bonk:

It would move your center of gravity by zero.

If you piss 0.5 kg (that's a two cup piss man) and you weigh 100 KG (with suit an all), and you shift the piss weitght by 1 meter, your body would move 1/200th of a meter, or 0,5 cm. Your center of gravity remains unaffected. Then end velocity after the piss lands into the boot would be ZERO. Action-reaction would propell you while the piss flies, but the piss hitting your boot would bring your CG back to point zero.

I'd rather die not in my own piss. Personnal choice, only personnal choice.

:-)

Rapid throwing motion does not work for after the throwing, a force is exerted upon your body to STOP your arm.

There are violation of action-reaction law, but they are not recognized by mainstream physics. And they don't happen with linear motion. They require transfer between variable speed rotational movement and linear movement. It is alledgedly produced by compounded multirotational-linear movement.

There are patents and claims of inertial thrusters that eject no mass.

Nasa is apparently working on one.

A fantastic source of info for that is Infinite Energy Magazine.

Google it and you'll hit right on it.

Have fun !


IMO, the best way to get out of it would be to puncture a cooling fluid line (providing you have your Space Swiss Penknife handy) . It would get ejected at the suit pressure, and have more weight than the gas. Gas has higher theoretical yield, but in that case, since you probably don,t carry a large mass of gas, I think it better to eject coolant (but not all of it unless you want to turn into a half-frozen half sizzling barbecue.

Yes, you would only gain benefit for the brief period your arm is in motion. A 'punching' motion would be more helpful that a throwing motion. And both would cease to help once your arm stoped moving.

Better to drown in your own piss than someone else's amber stream... :cool:

LOL ! You have a point !

Another kewl one... The Liar's Paradox

The paradox goes like this:

1. Epimenides is a Cretan.
2. Epimenides states, "All Cretans are liars."



Solution at http://david.tribble.com/text/liar.htm

Um... ok... will take a stab at this... July 25, 2003... That sounds like a HOT DATE to me... :bonk:

how about (3^2)(sqr(4))(5)=90


sqr means square root of

QED

Wow we've really got some smart cookies here! :D

Well, you did add a "2" and therefore not only adding symbols!

damn rules:D

Brian dies in Texas, while Cathy dies at sea. Cathy's death was a cause for much celebration, after Brian.

Why?

Well thank you everybody for making me feel really retarded today. I can barely do the little trivia questions on placemats at the restaurant. :bonk:

Hey, wsjb78, did yo ever use Maple (Waterloo) ? I feel the urge to have it nowadays, just to tinker and fool around with it.

I used Maple back at highschool for some math experiment. we went to the polytechnicum in zurich for it to get some input.

We did finally a programm with maple that did graphically compute a constant temperature of a room.... well, the distribution of different temperatures in a room until a steady case was received.

Using with one ofen and one window.... you first needed to place the window, then place the ofen somewhere and you had to define how much temperature the ofen exterted and then just have the whole thing iterated until you got a steady flow temperature!

Was quite cool!

I was just reading some of the older posts and came accross this one.

Anyone have any new brain teasers?

Cathy and Brian were names of hurricanes?

I now have Maple 7. It's an incredibly cool software !