Lighthouses help ships to know exactly where they are when they are sailing near the coast, and also warn where there are dangerous rocks and currents. Could you build a working model of a lighthouse, with a light that flashes on and off?
Levels of difficulty:
Level 1 - Make a model of a lighthouse tower Level 2 - As level 1, with a light on the top Level 3 - As level 2, plus a way to make the light flash on and off
Equipment: KNEX set, plus (for level 2) battery pack, wires with crocodile clips, light bulb and (level 3) push-button switch or similar.
Approach: Lighthouses have to be tall and strong. How could you make a tall tower with KNEX? How can you make the walls very strong, so they wont bend or break in a storm? For level 2, how can you fix your light bulb on at the top of the tower? How will you connect it to the battery pack? For level 3, what extra wires will you need to connect the light bulb to your switch?
A project to make a simple electrical circuit with a practical purpose, and also to build a strong structure.
Possible solution: See photo.
Before starting: Look at a picture of a lighthouse, and explain why lighthouses have flashing lights.
Conclusion: Firstly, draw the electrical circuit. Then, pretend there is a ship sailing through the classroom. Ask each pair of children to think of a special way to flash their light, so that each lighthouse flashes with a different pattern (eg one short flash followed by two long ones).