Popping Fun Lab

In Science Class a few weeks ago, we did a lab, called Popping Fun. This lab taught the kids how to mix compounds, to get a reaction. We had to mix baking soda with vinegar in a test tube,and try to get enough pressure in a test tube so we could shoot a cork across the room,to hit the window. The particular group I was in, tried to do this test about 4-5 times, before we figured out the combination. If i recall correctly, it was 25 vinegar 5 baking soda, but i am not sure on that.If we hit the window 3 times in a row,everyone in the group would get extra credit, and we all got extra credit.