(Physics for ages 8+)
Machines are all around us, and they can be very helpful for doing everyday tasks, like lifting or moving heavy objects. Have you ever used a wheelbarrow? Have you noticed how much easier it makes moving rocks or dirt than having to move them by hand?
The simple mechanics of a wheelbarrow makes it a great tool to move larger amounts at a time than simply using a shovel. Hydraulic machines are another way to lift and move things that are too heavy to lift by hand. In the video above, you can see just how easy it is to build your very own simple lift using the science of hydraulics. Here’s what you’ll need:
2 small oral syringes (10-25 mL or CC)
Flexible plastic tubing (can be found in hobby stores or medical supplies)
Hot glue gun
Adult supervision (Adult supervision at all times please)
- Start by building the housing for your lift. Using the ruler, measure out the dimensions for 4 equally-sized panels. These exact dimensions may vary depending on the size of your syringe, but 4cm x 13cm is a good starting point. Additionally, you will want to measure out a base (13cm x 13cm), 2 tabs (1cm x 4cm) for holding the syringe inside the housing, and a
- After you have measured out all of your cardboard pieces, carefully cut them out using the box knife. It might be best if an adult does this step.
- In one of your panels (the 4cm x 13cm pieces), cut a small notch out in the middle of one of the short sides.
- **The next few steps involve hot glue, which can be very hot, as the name implies. Be sure you have an adult assisting so as not to burn yourself.
- To construct your housing, start by gluing one of the panels (NOT the notched one though) to the base short side down, as seen in the video. Then glue the other 2 unnotched panels to the first one and the base. You should see a 3-sided rectangular prism, or skyscraper-looking object, taking shape.
- Glue the 2 tabs to the “wings” of one of your syringes. This is shown very well in the video above, so be sure to reference it if you need the visual aid.
- You will then glue these tabs into the lift housing that you have started constructing. Be sure the plunger of the syringe is pushed all the way inside the syringe. Glue the tabs about 1 cm down from the tops of the panels so that the flat part of the sits plunger
- Cut about 15-20 cm of the clear plastic tubing and attach one end to the syringe within the lift housing.
- Now glue the notched panel in place to close off the housing. The notch should be carefully placed over the tubing, as you can see in the video.
- Add a dab of glue to the flat part of the plunger to attach the platform (8cm x 8cm piece).
- In a bowl, add a few drops of food coloring to some water and stir it together. Using your other syringe, draw as much of the colored water into the syringe as possible by pulling the plunger up.
- Attach the other end of the plastic tubing to the full syringe, and your hydraulic lift is ready for use! Simply push the plunger of the full syringe down, forcing the liquid through the tubing and into the syringe glued into the lift housing. Did it work? Did your platform move up? Test the power of your lift by adding heavier and heavier objects. What do you notice?
Hydraulics work by moving liquids, like the water in the syringes. Liquids cannot be compressed into a smaller volume. You can test this by filling one of the syringes with water, covering the hole with your finger, and trying to press the plunger down. Can you move it?
No matter how much pressure or weight that is applied to the plunger, you will not be able to push it down as long as the hole is covered. This cool property of fluids makes hydraulic technologies possible and allows you to move heavy objects with less force than would otherwise be needed.