Screws - A Ramp Around a Rod

A screw is a simple machine made by wrapping an inclined plane (a ramp) around a central rod. This design allows a small force applied over a long distance to be converted into a larger force, which can hold objects together or lift them. Everyday examples include screws, bolts, jar lids, and spiral staircases.

1. Begin with pictures of long ramps or staircases and explain how ramps reduce effort by spreading work over distance.
2. Show a spiral staircase or spiral parking garage as an example of how ramps can be wrapped around to save space.
3. Compare a steep path up a mountain with a switchback path, which works like a screw by making the climb easier.
4. Give each student a triangle of paper with the long side marked as the “ramp.”
5. Have them roll the triangle tightly around a pencil; point out how the ramp becomes a spiral, forming a screw.
6. Discuss how screws use this principle to hold things together or lift objects with less effort.

📄 A ramp wrapped around a rod - Inventors of Tomorrow: https://inventorsoftomorrow.com/2016/10/24/screws-simple-machines-activities-for-kids/

• Use clay or playdough to make spiral shapes that resemble screws.
• Demonstrate with real screws and bolts, turning them into wood or cardboard.
• Extend the activity by making paper beads from the rolled paper triangles for a craft project.

• Supervise use of sharp objects if real screws or bolts are demonstrated.
• Ensure pencils or other rolling objects are used safely to avoid poking.

• How is a screw similar to a ramp? (It is an inclined plane wrapped around a rod.)
• Why is it easier to use a switchback trail than climb straight up a steep hill? (Because the incline is spread out, requiring less force at one time.)
• What advantages does wrapping the ramp around a rod provide? (It allows long ramps to fit into a small space and lets screws hold or lift materials more effectively.)