Make a Pulley
Emergency! White water rafters have overturned their raft, and the speeding current is pulling them toward a waterfall. A helicopter zips in and lowers the rescue bucket. The distressed rafters climb in and are pulled to safety. What simple machine is at work in the helicopter bucket? Here's a hint: it involves a wheel, groove, and rope. If you said pulley, you're right! In this project, you'll use paperclips and string to make a pulley.
The helicopter bucket uses a pulley. Think of other examples of pulleys. Some that you might have seen are a construction crane, elevator, flag pole, old-fashioned water well, and exercise machines. Can you think of any others?
To simulate a helicopter rescue by making a simple pulley from household items.
- 2 paperclips
- 36 inches of string
- Plastic berry basket
- Small figurine
- Notebook and pencil
- Unbend the center of a Paperclip 1 so that it makes a hook.
- Tie Paperclip 1 to the end of a piece of string.
- Thread the loose end of the string through Paperclip 2. You just made a pulley!
- Put the figurine in your berry basket, and place both on the ground.
- Now, lower Paperclip 1 to hook the basket.
- Pull the loose end of the string through Paperclip 2, raising the basket.
Your helicopter rescue was a success! You created a pulley using paperclips and string, and you used your pulley to lift a basket.
Pulleys are all around us. Look at your window blinds. Notice that when you pull the string down, the blinds go up. This is a pulley at work. A pulley is a simple machine used to make lifting easier. If you drop your book on the floor, you can bend down and pick it up, no problem. When it comes to putting a roof on a house, though, construction workers can't just bend down and pick it up since it is so big. A pulley allows the work to be done from a crane; the machine construction workers use to lift heavy materials. The force in the crane pulls down, and the roof goes up. Pulleys are useful tools that can even be life-savers. Just ask the white water rafters!
Now that you're a pulley expert, it's time for more guessing and testing. Think about the strength of the different parts of the pulley: What other items do you think you can lift? How many can you pick up? Which would be easier to lift with your pulley: a book or a doll? Can your pulley be used to move things from side-to-side, or just straight up and down? Write down any guesses that you have, called hypotheses, in your notebook before testing your new problems.
Keep thinking like a scientist, and you can conduct endless investigations with your paperclip pulley.
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.