Here is our write up
Our Question/What we want to find out?:
How high will the geyser go if I add 11 mentos to a 2.25ltr bottle of diet coke?
How long will the geyser last before it runs out of energy?
We think the geyser will go 2m into the air.
We think the geyser will last for 5-10 seconds
Materials/What we will use:
1x 2.25ltr bottle of diet coke (Preferably warm or at least at room temperature)
1x Geyser tube (Purchased from the 2 dollar shop) you could make your own
1x safe area to complete the experiment (Coke will go everywhere)
Process/The steps we will take:
Observations/what we saw/diagrams:
As Hamish dropped the Mentos in the 2.25ltr coke bottle, it started to fizz up at the bottom and then the geyser spat out, the geyser went up just above 3 metres. It lasted for 10.89 seconds. As the geyser reached up high it sort of flaked out like a fountain. As it got longer it slowly came down back into the bottle, and fizzed out. Once it was over you could see the mentos floating in the bottom. Only ⅓ of the coke was left. The rest of the bottle was filled with coke foam.
Our hypothesis was that the eruption would last 5-10 seconds and be 2m tall. But the experiment confirms it was 3m tall and lasted 10.89 seconds. Also the inch diameter was 4 inches. The best way to describe how it reacted is: the explosion went up like a stream then came down in separate frothy bubbles. There was only 1 third of coke left in the bottle, the rest was froth.
Conclusion/Answer to our questions:
A1: The geyser went above 2 meters. The geyser actually went just above 3 meters.
A2: As the geyser went up, it stayed up for 10.89 seconds.