Build an Egg Transporter in Physics Class

[brice]

Hello everyone,

In my physics class, we need to build a machine that has to hold an egg and move across two meters on a rope as fast as possible.


There are some rules to follow:

- The machine must not be bigger than 25 cm long and 50 cm large. As you can see there is no height limit.

- No part of the machine must touch the ground or the wood that holds the rope.

- We can't push the machine.

- The egg must be over the rope.

- These are forbidden: machine that can cause injuries, gas under pressure, chemical reactions, heat (flames), electricity, batteries, engines and lasers.

- The rope will be a 1/4 inch yellow rope.

- The machine must make it in less than 30 seconds.

That's it for the rules. Now let's see how the rope will be. On the first round, the rope will be horizontal. For the second round, the rope will have an angle of 20 degrees(going up). For the third round, the rope will have an angle of 45 degrees.

Well that's about it. The attachment is a zip containing an image explaining how the rope and stuff will be set up.

Thank you a lot for helping me,
Julien.

 

[brewnog]

Zip is corrupt, or is it just me?

 

[brice]

Well, it works for me, maybe it's because you don't have the lattest vresion of winzip.

 

[brice]

Comon you guys are geniuses! Don't you have any ideas?

 

[brewnog]

Well the zip *still* doesn't work for me, but my thoughts involve a pulley wheel on the rope being spun by means of a falling weight on a string wound around the pulley spindle. Obviously you need to think up some method for keeping the egg above the rope. But as I say, it's difficult to picture the problem only using your description.

What are your ideas?

 

[brice]

Hey,

Thank you for your idea. I was thinking of using ballons filled with Helium to lift the machine when the slope of the rope gets very high. This was, i only need a simple way to make it on the horizontal slope. To get the egg above the rope i thought using a heavier materials at the bottom and lighter materials on top so the egg can aways stay on top. I just need to think about a way to make it through the horizontal rope using strings. I hope you can help me with that.

Julien.

 

[Cliff_J]

It takes an very large amount of helium to get much lift at all. Its like a couple large paper-clips per ballon.

A toothed pulley (think of teeth like thumbtacks that can get mechanical grip 'in' rope) would allow motion and traction. Using thumbtacks will turn the pulley/rope into a sprocket/chain. Using something like a clock spring could provide propulsion at low weight. Then you'd need to work out the expected weight and figure out the gearing or spring strength to get it up the inclines, it would fly on the horizontal section.

Cliff

 

[hitssquad]

File not corrupt

Zip is corrupt, or is it just me?

If I left-click on it, XP says it is corrupt. If I right-click on it and save it to my desktop, I can then right-click on that to extract it and all is hunky-dory. http://www.efn.org/~callen/ropechallenge.jpg it is on my webspace.

 

[hitssquad]

Top fuel dragsters and egg transporters

To get the egg above the rope i thought using a heavier materials at the bottom and lighter materials on top so the egg can aways stay on top.

You don't necessarily need the bottom to be heavier than the top. You just need it to have more force-leverage. I.e., if it extends far below, it can be much lighter than the egg and still keep it on top. Top fuel dragsters operate on this principle, with a very light but very long front end keeping the dragster from flipping over backwards during acceleration.

 

[brewnog]

Helium balloons are arguably 'compressed gas', which is forbidden.

Sorry!

hitssquad,- cheers for that.

 

[brice]

Thank you guys for answering.

Cliff_J:

Ur right, i don't think helium will work since its not enought powerfull. Your idea using thumbtacks is pretty good, but is a clock spring enough powerfull to lift that kind of machine with constant force?

hitssquad:

I see, this is going to help since the clock spring would not have a lot of power to lift a weight. I'll keep your principle in mind.

brewnog:

Yep, you'r right. It is compressed gaz but its not very compressed. I'll forget this idea then


Where should i start with? (we are going to start making the plans and buying parts this thursday.

Thank you very much,

Julien

 

[sheldon]

I am not sure if this would work but take a tube with a very strong spring inside and a large weighted object hooked to it, compress the spring and have a hair trigger hooked to it and I think it would propel forward even though the weighted object would still be attached. I know have a string hooked to the object so it will only throw it out so far allowing it to be safe.

 

[karmicthreat]

A neat little contest. Another way you could do it is to just use a hanging weight since there is no height restriction. Just use that mass to power a couple wheels clamped together on the rope. The diagram is too low rez for me to see how much that weight in the diagram weighs, but you could do something like have that hanging mass charge a spring and use that to climb higher on the rope. There is a whole bunch of stuff you could do.