Newton's 2nd law: Inquiry approach

Contributed by Anna Thanukos, UC Museum of Paleontology, UC Berkeley, based on an activity by Cecilia Tung
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Summary

In this lab activity, students act as fellow scientists and colleagues of Isaac Newton. He has asked them to independently test his ideas on the nature of motion, in particular his 2nd Law. The emphasis here is on the process of science rather than the actual results. Students need to focus on how they would design a procedure to test Newton's hypothesis and then communicate that idea to others.


Learning Goals

Newton's 2nd Law

Students will learn that:
  • Science deals with the natural world and natural explanations.
  • The process of science involves observation, exploration, discovery, testing, communication, and application.
  • Scientists decide on their own methods of investigation.
  • Experimentation involves controlled manipulation of variables in order to establish causal relationships.
  • Scientists organize data in tables and display data visually in graphs.
  • Scientists aim for their observations and tests to be replicable.
  • Multiple trials of an experiment are required to see patterns in the data. Scientists decide how many trials to run.
  • Error is present in every scientific experiment.
  • Scientific experimentation does not prove a relationship between variables.

Context for Use

This is a high school or college level lesson for a small class (<30). It should be done in a lab setting. As students will be developing their own procedures, you will want to provide a variety of materials from which they can select. These include standard high school physics lab materials: dynamics carts (small carts with wheels), stop watches, meter sticks, pulleys, string, and masses. Depending on the level and background of the class, you may want to provide a CBL (calculator based laboratory), force sensor, and accelerometer or photogates in order to collect more precise data. The activity takes 1-2 hours.

Description and Teaching Materials

Teaching Notes and Tips

This is a lab activity that is usually given to students with a predetermined procedure that they follow. In this version of the lesson, students must come up with their own procedures to verify Newton's 2nd Law. As the emphasis here is on the process of science rather than the actual results, some students may not see this as "real" science. It is in fact a huge part of the scientific process carried on by real researchers. It is important for students to realize how much time can and should go into designing a good procedure.

Within this activity, Newton's 2nd Law is referred to as a hypothesis as the students are supposed to be acting as contemporaries and testing his ideas.

Instructions have purposely been kept to a minimum to that students come up with their own ideas rather than follow a specified method. You may need to add further guidance for some students.

Assessment

References and Resources