While watering the grass with a water
hose, I tried to use my finger to stop the water a few times, but it
didn't work. The water rushing out of the hose had too much pressure. My friend told me that they
don't have this much pressure at their house. They live up the hill,
just a few blocks away. I tried their water hose and could stop it
by my hand. That showed me that water pressure is not the same
everywhere. I was thinking about this for a while. First, I thought the
diameter of the pipe may be a factor, but that wasn't the case. I
checked them out and they both looked the same size. Thinking about
this experience raised many questions in my mind.
Now my questions are why does water
have pressure? Do all liquids have pressure?
How does the water pressure
change at different depths? How can we reduce or increase water pressure? Can we use
water pressure to do something, such as lifting a car, breaking a tree,
or digging into the ground? Any of these questions can be the
subject of a science project.