A marble run is a fun school project where you build a track and watch a marble travel from top to bottom. You can use pool noodles cut in half, paper towel rolls, cardboard tubes, tape, and cardboard supports. This project helps students see how gravity pulls objects downward and how ramps, curves, and drops change motion.
The goal is to design a winding track that keeps the marble moving for the longest time without falling off.
Key Facts
- Gravity pulls the marble downward and starts the motion.
- Higher starting points give the marble more potential energy.
- Potential energy can be written as PE = mgh.
- Moving marbles have kinetic energy, which can be written as KE = 1/2 mv^2.
- Gentle slopes usually make the marble move slower than steep slopes.
- Curves, loops, jumps, and rough surfaces can slow the marble and make the run last longer.
Vocabulary
- Gravity
- Gravity is the force that pulls objects toward Earth.
- Potential Energy
- Potential energy is stored energy an object has because of its height or position.
- Kinetic Energy
- Kinetic energy is the energy an object has because it is moving.
- Friction
- Friction is a force that slows motion when two surfaces rub against each other.
- Slope
- Slope describes how steep a ramp or track section is.
Common Mistakes to Avoid
- Making the first ramp too steep, which is wrong because the marble may go too fast and fly off the track.
- Leaving gaps between track pieces, which is wrong because the marble can get stuck or fall through instead of rolling smoothly.
- Using weak supports, which is wrong because the track can bend, tip, or collapse while the marble is moving.
- Testing only at the end, which is wrong because small problems are easier to fix when each section is tested as it is built.
Practice Questions
- 1 A marble run starts 80 cm above the floor and ends 20 cm above the floor. How far does the marble drop?
- 2 A marble takes 12 seconds on the first design and 18 seconds on the improved design. How many seconds longer did the improved design last?
- 3 You want the marble run to last longer without stopping. Explain whether you would add a steep drop, a gentle curve, or a rough flat section, and why.