Let’s imagine two scenarios:
1. Two identical vehicles, each of whose speedometers reads 50 mph, travel toward each other and experience a head-on collision.
2. Another identical vehicle, traveling at 50 mph, hits an unmovable, unbreakable and impenetrable rock wall.
Which collision is more severe from the viewpoint of one of these vehicles?
This is a classic question that has been discussed by many for decades. It has even been the topic of Mythbusters television shows, in which real cars are put to the test—kind of an expensive, but captivating, way to investigate the question!
Now your students can do experiments with this question in the lab using PocketLab Voyager and some inexpensive, but very sturdy, powered cars that come with Speedway Wonder™. In the process of their work, they will be employing all eight NGSS Science and Engineering Practices. A suggested approach to this investigation includes the following ordered sequence of activities:
1. Present the problem to your class.
2. Have the class break into groups, share their thoughts, and hypothesize an answer to the question. They should do this without accessing the World Wide Web.
3. Ask the students to design and conduct experiments using PocketLab Voyager and Speedway Wonder™, in an effort to test their hypotheses.
4. Have each group discuss how their experiments support or refute their hypothesis.
a. Did they just do one trial for each scenario, or do multiple trials and compute averages?
b. Did they do anything to make sure that all cars were traveling at the same speed?
c. Was Voyager securely fastened to the powered car?
d. Was their wall reasonably close to being “unmovable, unbreakable, and impenetrable” for purposes of this investigation?
e. Did they have the data collection rate in points/second for the PocketLab app set as high as possible?
f. Did all cars have the same mass/load?
5. Now let the students do some internet research on the question. A good starting point might be to have them do a Google search for “head-on collision vs wall”. There will be abounding information on this topic. From their research, what appears to be the correct answer to this question?
6. From their research, what are some factors that affect real-world answers when comparing severity of the two scenarios?
7. What are some of the advantages of performing this investigation in a lab setting using PocketLab Voyager and Speedway Wonder™ track and powered cars?
