What is the best way to empty a liquid from a container? I don’t mean a water gun, because that’s the most fun. I mean like what’s the fastest way to drain water from a water bottle or a milk jug? Today we’re going to learn a bit about fluid flow with a couple of cool activities.
If you’re able, we’re going to make a vortex bottle, too!
Just a tip: We’re going to be filling up and draining containers with water, it’s best to do this over a big bowl or plastic tub to save the water to water plants.
Materials:
- Two plastic water bottles with their lids; identical ones are best.
- Water
- A container to catch the water when you pour it out
- A stopwatch (on a phone or computer)
Optional to make the vortex bottles:
- A drill with a large bit (½ inch)
- Glue gun
- A pencil
Procedure part 1:
- Fill two water bottles or plastic jugs with water
- Whenever you dump water out, try to catch it in a bucket so you can reuse it
- Using your stopwatch, see how long it takes for the water to drain from one of them by simply turning it upside down
- For the second bottle, when you turn it over to drain you will be spinning it like in the image. Make sure to time it!
Procedure part 2 to make a vortex bottle:
Procedure part 2 to make a vortex bottle:- If you have access to a drill with at least a ½ inch bit and a glue gun, here we go! Of course, ask your parents’ permission or to help out before you do this.
- Take the bottle lids off the containers and put them together so the two tops are facing each other
- Use the drill to drill a hole through both bottle caps. The bigger the hole the easier this will work
- Warm up the glue gun. Put a pencil through both holes of the lids so they line up easily for the next step.
- Use the glue gun to connect the two lids. Make sure not to clog up the hole with the glue. Get close to the pencil but not too close that it gets stuck.
- Remove the pencil.
- Fill up one of your water bottles with water and put the double cap on top
- Put the empty water bottle on top of this and screw it in
- Turn the full water bottle over and spin it again to get the water to spin in a funnel shape (called a vortex)
- If the hole is too small, it will take some serious spinning to get it to spin through like in the photo. You might have to drill the hole a little bigger to get it to work!
Explanation:
When you first tried to just let water fall out of the bottle it didn’t really flow well. You probably noticed bubbles of air trying to go into the bottle as it sputtered a bit. When you spun the bottle, however, it allowed air to flow in as it formed a vortex and thus made the water drain faster!
Going further:
Try this out with different-sized containers. Two-liter bottles, water jugs, etc. Just remember to not waste the water if you can help it!
LOOKING FOR MORE science experiments? Find them here!
About the author:
Steve Davala has been teaching math and science to middle and high schoolers since 2000. He writes books, plays music, carves wood and he loves learning new things. Ask him a question at steve.davala@gmail.com.
