Energy systems
Invent-a-Wheel
3. Ramps and Sleds
Overview
Students explore how putting an object on a ramp can get it to move “by itself,” how to prop up the ramp with a stand, and how ramp height affects whether or not it will move. The lesson ends with an experiment: predict and then test to find the smallest ramp height that will make the sled go down.
Here is another video on how to make the ramp stand
Advance Preparation
Materials
Procedure
Class meeting: Ask students if they have ever been on a sled, or seen one on TV:
2.
Make a sled: Provide large cardboard sheets and small rectangles. Ask students:
3.
Propping up the ramp: By now, students should have figured out how to use the ramp to make the sled go down. However, they may be holding up one end of the ramp themselves. Ask:
4.
The ramp stand:** The objects students use to prop up the ramp may not be stable. Also they are all different, making it hard to tell how high the ramp is. Provide each student with a ramp stand template and a ramp with slits. Show students how to fold the stand and assemble it with the ramp. (Here is a video on making a ramp stand). Directions for making a ramp are included in Lesson 10 as an example of a “How-to Book”) Ask:
5.
An experiment: How high does the ramp need to be? Introduce what it means to do an experiment. First we make a prediction. Then we test the prediction to see if we were right. After the experiment, we write down what happened.
6.
Outcomes