Pulleys
Construct a pulley out of simple materials.
What You Need
Materials per student
- Paper cup
- String (1.5 metre long)
- Magnet
- Paperclip
Guide:
Safety Notes
Ensure you are familiar with Let's Talk Science's precautions with respect to safe virtual delivery to youth.
What To Do
To construct the pulley, each student will:
- Poke two small holes at opposite ends at the top of the cup.
- Cut a piece of string (around 25 cm), thread it through the holes and tie a knot at the top to make a small handle.
- Stick a magnet onto the bottom of the cup.
- Using the rest of the string, they will tie one end to a door handle, thread the handle of the cup onto the long piece of string, and hold the other end of the string. The cup should be hanging from the string with the magnet facing down.
- Check to see if the cup will glide along the string up and down.
- Place a paperclip on the ground, and try to pick it up with the magnet on the cup by gliding it along the string.
Discovery
A pulley is a simple machine that can help us lift heavy objects off the ground - they help us by reducing the force we would need to use to lift an object. Pulleys have a rope that moves along a wheel (or handle in the above pulley) and can move in two direction to pick up a heavy object and then lift it. When a pulley is used, the force is always going in the opposite direction of the object being picking up.
What's Happening?
A pulley is a simple machine that can help us lift heavy objects off the ground - they help us by reducing the force we would need to use to lift an object. Pulleys have a rope that moves along a wheel (or handle in the above pulley) and can move in two direction to pick up a heavy object and then lift it. When a pulley is used, the force is always going in the opposite direction of the object being picking up.