Project Overview
Student Learning Objectives
Content Material
Links to Course Competencies
Supplementary Resources

Calculate the Mass of The Earth


Time: Approximately 50 minutes


Materials: Online access, paper and pencils, calculators, printed Student Directions and Student Worksheets, if desired


Prerequisites: The student should be able to use a calculator and scientific notation, have an understanding of circular motion, of Newton’s Laws of Motion, and of Gravity.


Implementation: This RWLO can be used as an in class exercise if online access is available, or as a homework assignment. This exercise is relevant to the topics of Newtons Law of Universal Gravitation, circular motion, and the difference between weight and mass.

The instructor should thoroughly familiarize himself or herself with the J-Track 3D windows that provide the satellite data, and the steps in acquiring the on-line dry mass of satellites from the NSSDC Master Catalog prior to beginning this exercise.

The exercise has students fill out and complete a worksheet, the instructor will need to print enough copies for his or her students, and familiarize themselves with the calculations.

    1. Prior to class, familiarize oneself with the J-Track 3D windows and NSSDC Master Catalog.
      NOTE: Students will have trouble with J-Track 3D and the NSSDC Master Catalog. Emphasize that they must turn off their pop-up blocker for J-Track 3D. Emphasize students may need to pick a different satellite if the one they choose does not show up in the NSSDC Master Catalog. Using just the satellite name without a number (in the Master Catalog) will often bring up the needed information.
    2. Print copies of the Student Worksheets and Student Directions.
      This is the Student Worksheet in a Word Document
      This is the Student Directions, also in a Word Document
    3. Provide instruction to students in Key Concepts (gravity, acceleration, circular motion, centripetal and centrifugal force, Newton’s Third Law) if necessary.
    4. Hand out and discuss the student procedure. The instructor should demonstrate the J-Track 3D data windows and teach online procedures if necessary. The Instructor should clearly tell students that they will need to look at several satellites. Data for all satellites is not in the NSSDC Master Catalog, students will need to try several to find a satellite for which on – orbit dry mass is given. .
    5. Hand out and discuss the Student Worksheet, and grading.