LEGO Day Science Project

January 27, 2023 |

The colorful plastic bricks known as Lego have entertained children (and adults) around the world for nearly 70 years. Lego is used to make toy buildings, vehicles, creatures, machines, anything imaginable — and they can be taken apart and put back together as often as you’d like. That means endless creative play. National Lego Day, on January 28, celebrates these incredibly ingenious and enriching toys.

STEM Project: Lego Zip Line! Explore friction, gravity, slope and more!

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  • Basic LEGO® bricks
  • LEGO® Guy or Gal
  • Parachute cord or string

STEP 1: Build something for a LEGO® guy to sit in as he zipped down the line. This is a great opportunity to test out those master builder skills!

Start by putting a LEGO minifigure on a base and build up and around him! When you reached the top, leave a space for the parachute cord to slide through.


STEP 2: Secure the parachute cord to door handle and then securing the other end to an anchor point – something lower, such as a chair or workout weight.

Experiment: Move the anchor point closer to shorten the slope or farther away to increase the slope and see how fast the LEGO® minifigure travels. Change the anchor point height to see how that changes the rate of speed. Here’s a good time to explore some scientific concepts like slopes, gravity, and force!

Make sure to ask questions!

  • What makes the man travel faster down the zip line? 
  • Is a steep slope better?
  • What happens to the LEGO® man when he gets to the end?

Take it Farther: In our Engineering Challenge class we used a zip line to learn about balance and center of mass. Once you have explored friction, gravity and slope, take on an added challenge to send a minifigure down riding on top of the zip line. Try it, what happens? If it flips to the bottom, think about why? Where could you add weight to the set up so the weight above the line was balanced?

Engineering Challenge Class

*CREDIT: Huge thanks to Little Bins, Little Hands for this Experiment Idea!

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