Mentos; Take 3: The Battle of the Sodas!

Given the high number of comments that the previous two mentos and diet soda postings generated we decided to do a third experiment. On one hand we wanted to create a higher jet, so to achieve that we drilled a 1/4" hole on the bottle cap of the 2-liter bottle. But then the question came: "Coke or Pepsi?"...

So we used both. And to add more power to the reaction we skewered 4 mentos with a paper clip and dropped them into each one of the bottles.

The result..... see the video below. Coke had a higher stream it went approximately 25 to 30 feet high. Pepsi came about 5 feet lower.

We challenge all of out blog visitors to up the ante, and create your own Mentos experiment (Don, I know I can count on you bud)......

The pictures show the bottlecaps with their perforation and the amount of soda that was displaced after the reaction.

The pepsi bottle displaced a total of 1,150 ml (or cm^3) while the coke bottle displaced a total of 1,100 ml. The orifice in the bottle caps was 5/16" (or 0.793 cm). The time it took for the liquids to be displaced was between 7 and 8 seconds. So the average velocity of the soda at the orifice was 309 cm/s (10 ft/s) for the Pepsi , and 297 cm/s (9.75 ft/s) for the coke! That gives us an approximate thrust value of 0.47 N (3.4 lb.ft/s^2) for the Pepsi and 0.43 N (3.16 lb.ft/s^2)...... this is just an approximation and some variables have not been taken into consideration such as the density of the fluid at the nozzle and the pressure differential of the fluid at the nozzle and the atmosphere...

Send us your ideas for future experiments on a comment to the blog!