Best way to launch a marshmellow?

[physicscrap]

Best way to launch a marshmallow?

I have a limit of $20 to build a small launcher. It will launch a large marshmallow. What is the best way using items bought from any retail stores? It has to land in the same place consistantly and for 50feet.

I am thinking something along the lines of spinning around a axis and hitting a stopper and it flings out. Also possibly using CO2 as the pressure. Wonder if it is possible to make it spin to reduce wind disturbance?? Any suggestions?

Maybe a large bolt with a nut on it, somehow CO2 can spin the nut and the marshmallow being attached to a rod sticking out from the nut will rotate very fast then stop so the mallow will fly off. I don't know!

Oh and I thought of a tube with a case for the marshmallow that would fly off in air. but htat would seem to alter the marshmalow each time I would think. Need to hit a target 50ft away horizontally.

 

[daniel_i_l]

try putting it in a tube a little smaller than the marshmallow, then seal one end of the tube and connect a pump to the other end. then work the pump to increase air pressure in the tube and quickly open the other side of the tube. sort of like an air gun. or fou could make something like a crossbow...

 

[physicscrap]

It has to have consistant results. A pump would be hard to keep constant pressure for 3 tries. With a $20 budget, i don't know about a gauge.

A crossbow is an option. QUESTION: if the marshmallow were to have a spin to it while in flight, will it reduce the wind on it? Will it make it more accurate?

 

[Danger]

If the rules allow it, I'd compress the marshmallow as much as possible, preferably into a bullet-shaped mould. Spin would definitely help in that instance.

 

[daniel_i_l]

Spin would help stabalize it, especially if the axis of rotation was in the direction of flight.

 

[rcgldr]

How about a sling shot mechanism? Latex tubing with 3/16 inch outer diameter, 1/16 inch inner diamater generates about 4.5lbs of tention when strecthed 300% (total stretched length is 4 times relaxed length). Strands from a bungy cord would work also. A local hobby store may have this stuff, as it's used to launch small radio control gliders (larger tubing is used for larger gliders). You can buy pre-made kits, but they cost more, but if the cost of the small amount of tubing you use out of the 50 feet or more in up-start or hi-start kit can be based on the proportion of length, it's well under $20.

There's a hand launch glider "up-start" at the site below for < $22, which includes string, a spike, and a long length of tubing.

http://www.hobby-lobby.com/histart.htm

 

[Danger]

A buddy of mine is reading over my shoulder and quite rightly pointed out that freezing the marshmallow pre-launch would be helpful.

 

[moose]

You could also, maybe, try using a trebuchet?

 

[Mk]

Make it denser. Freezing it was a good idea. That's all I could think of.

 

[Danger]

You could also, maybe, try using a trebuchet?

That crossed my mind as well. You'd certainly have no trouble getting the required distance with one of those. My only concern regards the accuracy. It might be tough to hit the same target consistently.

 

[kmarinas86]

Tape a marshmallow to one of these:

[MEDIA=youtube]9QuMASPj6Fg[/MEDIA][/URL]

[quote]1. open the [diet] coke
2. open up a napkin so its real thin and place it over the top of the open bottle.
3. Place the TUMS on the napkin
4. Screw cap back on over napkin and TUMS
5. Rip away the excess napkin
[New Step! Tape the marshmallow to the bottom of the bottle]
6. Toss the refreshing coke to your friend haphazardly making sure that the soda will weaken and dissolve the napkin. This drops the TUMS into the coke and starts the reaction
7. Laugh[/quote]

Make sure to follow the rules of the game. If you're not allowed to do the above, then don't do it. I don't know if you allowed to add muscle into the launch...

Edit: Finally, since you need to hit a target, I doubt the above will work! ;)

Also Fun - Mythbusters:
[PLAIN][MEDIA=youtube]aCS3BmKVHGA[/MEDIA][/URL]

 

[skywolf]

what if you melt it first?
would that help?
or would it just turn into a dangerous molten shotgun?

maybe not liquid, but mushy and more dense

 

[physicscrap]

You can't alter the marshmallow in anyway. They give it to you once the compitition starts. But would something that spins really fast on an axis be the best? I am not worried about distance, just accuracy. I need it to shoot in the exact same place each time. how would I make it spin? the axis of spin would have to be in the direction it is shot. It would have to be complicated i would think...

 

[DaveC426913]

I wonder how fast you could get a marshmallow to go with a railgun...

 

[Danger]

Okay, Physicscrap... since we apparently have to think inside the box, it's time to push the envelope. I would therefore recommend a sabot. Make a cup of the right size to hold a marshmallow, with spin-stabilization fins, and cut it in half (or more pieces) longitudinally. Use a gas cannon of some sort (a SuperSoaker feeding into a chunk of ABS tubing would work). Insert a gas-seal disk behind the sabot and let 'er rip. The fins will impart a spin to the sabot, and thus to the encapsulated marshmallow, as it travels along the barrel and for a short time thereafter. Then, the sabot will peel off and leave the marshmallow to continue its trajectory.

 

[B. Elliott]

I like the first reccomendation. After building quite a few spud guns myself, you can do it very cheap.

Bicycle pump: $2.29
http://cgi.ebay.com/FOOTBALL-BASKETBALL-BICYCLE-BALLOON-AIR-PUMP-P03_W0QQitemZ160036596629QQihZ006QQcategoryZ22691QQrdZ1QQcmdZViewItem?hash=item160036596629"

On/Off Ball Valve: $2.75
http://cgi.ebay.com/3-4-BRASS-BALL-VALVE-600-WOG_W0QQitemZ260038047118QQihZ016QQcategoryZ63904QQssPageNameZWDVWQQrdZ1QQcmdZViewItem?hash=item260038047118"

Add $15 worth of PVC piping and a type of sealer and you should have a decent small cannon if, you could figure a way to pump the air into a sealed chamber. Compress the marshmellow into a small pvc tube (1/2"?), pack it all the way down, pump up the chamber with the bicycle pump to whatever psi (gauge it by number of pumps?) and crack open the valve quickly.

Basing it off the number of pumps may possibly be more consistent than you think. Just a suggestion.

 

[fabricated death]

Hmm. This sounds a lot like a competition we have to do at our university.
Any chance you go to UCF?