I was watering my garden the other day, and I noticed (obviously), that the water came out of the hose faster if I stuck my thumb at the end of the hose. Then I suddenly remembered that in physics class, I was taught that gravity-powered water pressure should result in an exit velocity which was only dependent on the height of the water. Our water comes from a water tower, so I was confused about why putting my thumb on the hose should make a difference to the velocity. I asked my father if there was a water pump in between the water tower and our house, and he insisted that there was not. Then I asked him about this physics problem, and he said that he was sure that friction in the pipe was the cause of the behavior of the water in the hose. I have attached a word document in which I modeled friction. I got an answer which (qualitatively) fits reality. I just thought it was interesting that I (and I assume many other people too) have relied on pinching the hose to get water to come out faster for a long time without ever thinking about how it happened.