Have you ever wondered how we get water from a well? Learn about it with this DIY!
If you drop a bucket into a pool of water, you might be surprised to see it floating instead of sinking. This happens because of a property called buoyancy! Buoyancy is a floating force. It’s what lets a boat made out of concrete and metal stay above the water instead of sinking like concrete and metal would normally do.
When an object is placed into water, like a bucket in a well, it pushes some of the water out of its way. The water doesn’t like being displaced, so it pushes back on the object. The force it pushes back with (that’s buoyancy!) is equal to the weight of the water that got displaced by the object. So if your bucket displaces one gallon of water, the water will push up on the bucket with a force as strong as the weight of that gallon (about 8 pounds). If the bucket weighs less than 8 pounds, it’ll float. If it weighs more than 8 pounds, it’ll sink.
Buckets, boats, and other hollow things have a buoyancy advantage because they’re filled with air. Air is much lighter than water. A gallon-sized hunk of solid metal is definitely heavier than a gallon of water, but a gallon-sized bucket, with most of that volume taken up by air, will be lighter than a gallon of water. In order for a bucket to sink, you need to put something heavy in it to counteract the buoyant force. Try it out with your own well and bucket!
How we did it:
- 1 liter bottle
- wire cutters
- small container
- popsicle sticks (2)
- hot glue / hot glue gun
- electric drill
Gather your materials.
Cut off the top of the bottle.
Drill a hole the size of your dowel into each of the popsicle sticks about 1” from one end. You may need an adult to assist you.
Hot glue the popsicle sticks on the outside of the plastic bottle, near the top and on opposite side.Then, stick the dowel through them.
Cut a short length of wire about 3 inches long.
Make a small hole on opposite sides of the small plastic container. Then, make a handle using the wire. This will be your bucket.
It may help to use pliers to make the handle of the bucket.
Tie the end of the yarn to the center of the dowel. Then, cut the yarn so that the end of it just touches the bottom of the bottle.
Tie the loose end of the yarn to the handle of the bucket.
Decorate your well!
Now, you’re ready to test your well! Fill the bottle up about a ⅓ full with water. Then try to lower your bucket into the well. What happens? Does it fill with water?
Try putting two pebbles towards one side of the bucket. Does it fill up now?
Try putting other objects into your bucket to see what helps it sink and what lets it float. How many buttons do you need for your bucket to sink? How many paper clips? How many other objects? You can use this to figure out the strength of the buoyant force on the bucket.