Mobile, Ala. (WKRG) – For this Science Corner experiment, we will make water “walk” from cup to cup!
- Seven clear cups (plastic or glass)
- Paper towels
- Food coloring
- To start, you are going to take a sheet of paper towel and cut it in half length-wise, and then fold each of those pieces in half. You’ll need six of these if you have seven cups. (I used the paper towels that come in half sheets, so if you have full sheets, you will need to cut them in fourths)
- Next, you will fill four of the seven cups with water. You’ll want it almost to the top.
- Put a different color food coloring in each of the four cups with water in them.
- Stir to mix food coloring with water. e
- Next you’ll put your remaining three empty cups between the four cups with water in them. so they alternate cup with water, empty cup, cup with water….etc.
- Take your paper towel pieces, fold them in half, and connect the cups by placing the half of the folded paper towel in the first cup and the other half in the cup next to it. Then another paper towel with half in the second and half in the third cup. It will form a bridge between the cups. See video for specifics!
- After a couple of minutes you will start to see the food-colored water creeping up the paper towel. After a couple of hours you will see that the food-colored water made its way all the way up the paper towel and into the empty cup.
The water moves up the paper towel through a process called capillary action. Capillary action is the ability for a liquid to flow upwards, against gravity, in narrow spaces. Paper towels are made from fibers and the water travels through the gaps in these fibers. These gaps pull the water upward. The water is able to move against gravity (upward in this case) because of the attractive forces between water and the fibers. This is the same process that brings water from a plants roots up to its leaves!