The Wave - Student Activity
This activity guides students through the process of analyzing the motion of a water coaster at an amusement park as it comes down and hill and then rapidly decelerates when it hits a water pool. In addition to one dimensional kinematics, the worksheet prompts students to consider forces, Newton's Laws, and even the existence and causes of non-constant acceleration.
- Carefully observe the video
- Measure the displacement of the coaster car at certain times
- Calculate the initial and final velocity of the car
- Calculate the average acceleration of the car
- Consider the direction of the water's force on the car
Context for Use
I use this activity with my students at the beginning of the unit on forces as a way to re-emphasize 1D kinematics but at the same time to get them thinking about forces, friction, and Newton's Laws. Although it's quite highly scaffolded (giving the students quite detailed instructions) the instructor may need to offer additional information about forces and friction if the students haven't seen them before.
The activity takes about 20 minutes.
Description and Teaching Materials
Video file: The wave
Student video library - allows access to all videos for students, without links to instructor materials.
Here is a worksheet (Microsoft Word 2007 (.docx) 1.2MB Aug30 14) to guide students through this activity and worksheet solutions (Microsoft Word 2007 (.docx) 1.2MB Aug30 14) for instructors.
These instructions are highly scaffolded, giving students step-by-step instructions. An instructor may chose to provide less detailed instructions to encourage independent thinking and problem solving.
Teaching Notes and Tips
Although most of the kinematics that I do with my students is in the context of constant acceleration, this video depicts a situation where the acceleration appears to be quite variable. I think that is a great opportunity to let students know that the world is messier than the sanitized version that physics textbooks often present, but that doesn't mean that the math and analysis that comes from the sanitized version is worthless. It may not give you the whole story, but it's often a great starting point that will get you most of the way there.
There are several "Forces and Motion" DMV's (Direct Measurement Videos) in our video library that depict situations where the physics is almost identical, but the context and the specifics are very different:
Metal cylinder sliding across table
Student Riding a Rocket Powered Car (this video is no longer freely available)
References and Resources
Here is Hyperphysics' review of Newton's Laws
Design your own roller coaster here