PASCO : Physics - High School : Newton's Third Law

Force & Motion: Newton's Third Law

Determine the relationship between the forces that are exerted on two Force Sensors during a "tug-of-war."

Students measure the forces applied and easily observe the equal and opposite forces in a static tug-of-war. Students see that even though the force changes substantially, there is no net motion as long as the forces are in balance.
Enlarge graph.

Lab Summary:

In this exploration, students will use two Force Sensors to investigate Newton's third law of motion (Newton's Third Law).

Specifically, students will use Force Sensors to measure the forces involved in a tug-of-war. They will compare the plots of force versus time to determine how the two forces are related to one another; that is, the forces are of equal magnitude, but opposite direction.

Download free labs:

(student versions)

Computer-based lab (PDF, 956 KB)

Xplorer GLX-based lab (PDF, 232 KB)

Method:

Use a pair of Force Sensors to measure the forces during a tug-of-war between the two sensors.

Here's What You Need:

Required for computer-based lab:

(See lab download for Xplorer GLX-based lab requirements, which may differ)

Students explore 3 scenarios: pulling against each other, pulling against a force sensor attached to a fixed object, and pulling a larger mass. Enlarge graph.

Probeware

PASPORT Force Sensor (PS-2104) (requires 2)
Xplorer GLX Graphing Datalogger (PS-2002)
(or alternate PASPORT interface -- see other options )

Other Materials

Lab Manual:

The computer-based activity is included in Explorations in Physics (PS-2810). The Xplorer GLX-based lab is included in Physics with the Xplorer GLX (PS-2826). Both manuals are complete with Teacher Information pages, student instructions and handouts, and sample data.

For your convenience, we offer bundles which provide the probeware for the activities in the manual. For more, please see:
Computer-based Physics Lab Manual and Bundles
Xplorer GLX-based Physics Lab Manual and Bundles