Question
Create the body of your sled by using a part of the egg carton. What forces are acting on the sled as it moves down the “hill”? Can you change how those forces are working against your sled and make it go as fast as possible?
Materials
- wax paper
- plastic bags or plastic wrap
- felt squares or fabric
- pennies or anything to create weight
- egg carton
- clothespins
What to Do
- Take time to brainstorm your design. Write down some notes or draw a picture.
- Create your design using the materials.
- Use a stopwatch to record each sled run? Can you make an adjustment to make it go faster? Adjust and time it again. Record the results.
What is Happening?
Two forces affect the speed of a sled moving down a hill: gravity and friction. Gravity is the force pulling the sled downward. The greater the weight is on the sled the speedier the sled will be. Friction is the resistance between two surfaces. Rougher surfaces cause more friction and slow an object down. Smoother surfaces cause less friction and allow for more speed.
Activity add-ons:
Are there other materials you can think of that would add to the success of your sled? What are they? How would you add them to your design? Would these additions help your sled run down the “hill” faster? What would you do differently to your sled for someone who didn’t like speed and wanted to go down the “hill” VERY SLOWLY?
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