Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

Wearing a seat belt always does you good, it just always isn't enough. Since the time that your uncle died, :( there have been great improvements in vehicle safety both in the seatbelt construction and latching and in the cars themselves (we can thank the hundreds of crash dummies for that).

Seat belts rarely break in accidents and when they do, many times they have done their job and protected the person from the initial impact of the accident.

My brother-in-law was also in an accident were his seatbelt broke and he was thrown from the car (Blazer). But the belt broke after the Blazer rolled four times, If he had not been wearing the belt, he probably wouldn't have been alive to be thrown from the vehicle. By the time he was thrown the speed was reduced to a point where could survive the ejection.

Buckle Up Everyone! Especially if you are driving by the neighborhoods of Art, Elgin and Dylan when they are experimenting with Diet Coke and Mentos!

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

Maybe someone should start putting seat belts on those DC/M rockets people are working on. :p

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

Nah!! Personally I'm not at that "October Sky" status yet.. but someday.. oh yes, someday I will launch myself (or someone a bit lighter) in the air with Coke and Mentos. ;)

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

This sounds like the famous last words of Buster from Mythbusters... :eek:

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

You would definitely need a whole lot of coke and mentos...

Interesting Idea would be a steal reinforced bathtub (filled with water) and some Francium :yikes:


***200th Post*** :D

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

I don't know if this has been suggested. It trades power for control. You may not get the bottle to fly 50 ft, but maybe 15 feet straight up reliably is a nice trade-off.

Summary:
(a) suspend 5 mentos inside the bottle above the soda using a paper clip threaded through holes in the mentos. See here:
http://www.youtube.com/watch?v=GAHGz...0coke%20mentos
(b) Use a cork to hold the pressure until it builds.
(c) Construct a rudimentary launch platform from another 2 liter bottle so it launches straight up.

Details:
(1) Buy a cork that will fit firmly into the mouth of a 2 liter diet coke bottle. They have these at Michaels for <$2 for 4 of them.

(2) Create a launcher. Take an empty 2 liter bottle. Remove the label and soda. Use a box cutter or exacto knife to cut the bottle in half with a clean straight cut. 1/2 inch above the halfway point is actually perfect (yes above). Throw out the top of the bottle. The bottom will be your launcher.
(You will put the corked full bottle inside it and turn the whole assembly upside down to launch.)

(3) Prepare mentos. Take four mentos (5 is slightly better but dips into the soda and causes permature mixing thus ruining the launch.) Poke a hole through the centers of the mentos. I use a large thick paper clip or very thin nail for this because a normal clip just bends. String the four mentos through a small paper clip and then press the end of the clip into the bottom (inside) of the cork. The mentos need to be flush against the cork or they will mix with the soda too early.

(4) Cork the rocket. Open a new Diet Coke 2 liter bottle (Actual Diet Coke Brand is reported as the best, adn Dieat Coke beats non-diet becuase it's less sticky to clean up). Push the cork in as tightly as possible being careful not to crush the bottle and make sure NOT to let the mentos hit the soda!! Take the launcher and place it over the top of the rocket. You can get a little airtight seal here but don't worry if not - the main importance of the launcher is to hold the bottle upright.

(5) Turn the whole thing over (do not shake), and place upside down on the pavement and immediately back away. Don't hesitate because it can go off pretty fast.

The rocket should shoot upward maybe 15 feet or so. The trick is getting the cork as tight as possible. A rubber stopper might be better than a cork but I didn't try that. Then again if too tight you're back to the problem with the cap (not coming off until you destroy it). A 20 oz bottle might work even better, less weight, but I didn't try that. Also try a few more mentos and dump a little soda out first - more air space, more released gas should cause a faster and more explosive release???

It seems fairly safe, especially compared to slamming the capped bottle down, but use caution, consider eye protection, and of course avoid young kids around. It can still go at odd angles. Have fun.

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

Both types have been tested, and Diet Coke seems to project out more liquid than regular coke.

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

That's cause it's more carbonated :D

http://blog.sciam.com/index.php?titl...&c=1&tb=1&pb=1

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

that is only speculation: I think its because regular Coke is so syrupy - it has a much higher viscosity - its more like carbonated corn syrup.

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

Fatal flaw in that theory; my testing showed that cold coke barely reacts at all, compared to room-temp coke.

Someone needs to test this.

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

if surface area is the trigger then confectionery sugar, charcoal from an aquarium filter, or talcum powder might work better.

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

I imagine Diet works better because its much lighter than regular, so the same amount of CO2 "thrust" causes further projections.

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

Should probably stick with mentos because:

Confectionery sugar will most likely turn into sticky blobs

Charcoal is nasty

Talcum powder (at least the real kind) is a carcinogen! :ahh:

But if wax works you could probably just drop a candle in the coke and then re-use it, which would cut costs and not be sticky.

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

I cant see a candle having a lot of surface area. A candle is as smooth as, well, as smooth as wax

the charcoal used in filters has a very fine and grainy surface - thats why it makes a great filter, there is so much exposed surface area in a small handfull of the stuff.

Nobody drinks this stuff off the driveway after the launch, do they?!

you dont scoop it back in the bottle and put it back in the fridge (I hope) :ahh:

Re: One upping Dave: A Diet Coke and Mentos Rocket!
 

Well... my little brother tried it (Mentos fueled of course) and according to him it has a killer aftertaste. :yikes:

What I meant was that charcoal would make a would make worse mess (black) than Mentos.