A sensor opens the door: “if — then” logic
A ball rolls down a ramp and bumps a sensor, which turns green and removes the support under a second ball. Built from blocks.
2D
Age 8+10 min
Logic & robotsMomentum & collisions
Loading simulation…
Press “Run”. Bodies move by the laws of physics: gravity, friction, elasticity.
What the experiment shows
Robots follow rules: “if the sensor fires — do an action”. Here the condition is a touch, the actions are a colour change and the support disappearing.
How to run it
- Open the “Logic” tab on the left and read the rule.
- Press “Run” and wait for the sensor touch.
- Change the condition to “key is pressed” and open the door yourself.
Questions to discuss
- What is the sensor and what is the actuator in this chain?
- How to open the door only when both balls arrive?
The science
Automation is made of conditions and actions: a sensor measures, a rule decides, an actuator acts. Shop doors, traffic lights and robot vacuums work this way.
Try it at home
Set up dominoes so that the last one hits a lamp switch.
What to change in the editor
- Add a second rule: when the sensor fires, push the prize ball.