Uniform Circular Motion
Project Overview
This RWLO will concentrate on the concept of uniform circular motion. Because the
speed is constant for such a motion, many students have the misconception that there is
no acceleration. At the root of this problem is the fact that students forget that the
acceleration of an object changes its velocity, not only its speed.
Using real time data from satellites in orbit, students will be able to determine the orbital
radius of the satellite and calculate its velocity and its period of rotation. Students then
will use vector algebra to determine the magnitude and direction of its acceleration.
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Uniform Circular Motion
Student Learning Objectives
As a result of this lesson students will be able to:

Draw and read vector diagrams.

Calculate the orbital radius and the period of a satellite

Calculate the magnitude and direction of the velocity of an object in a circular
motion.

Calculate the magnitude and direction of the acceleration of an object in a circular
motion.

Have a better understanding of the vector nature of both velocity and acceleration
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Uniform Circular Motion
Procedure
Time: approximately 100 minutes.
Prerequisites: Students should have knowledge of linear kinematics and graphical
methods for addition and subtraction of vectors. Students should also have some
knowledge of right-triangle Trigonometry. Since EXCEL will be used for presenting the
data, they should be familiar with the software.
Implementation: this RWLO serves as an introductory lesson to the study of uniform
circular motion. It should be used in the classroom. Students can work individually or in
groups of up to three students. All members of the group should have the same data.
Steps:
1. Based on the definitions of velocity and acceleration, students will answer questions
in the Worksheet 1 handout. Distribute the handout and allow for 10 – 15 minutes for
this activity. Students should discuss the concepts, but each student should answer
the questions independently.
2. We will introduce the study of uniform circular motion by analyzing real world data
and drawing conclusions. Distribute the Worksheet 2 handout. Collect data by
accessing the J-Track Satellite Tracking web site. Students need at least 11 to 15
data points. The information in these sites is updated every minute. To calculate the
orbital radius of the satellite students will need one point close to the equator, latitude
at or near 0°.
3. To calculate velocities and accelerations, students will need the distance traveled by
the satellite in each time interval. Using the information about latitude and longitude,
access How Far Is It? web site to find the distance between two points. The distance
given in this site is on the surface of the Earth. Students will need to find the distance
traveled by the satellite.
4. Distribute and discuss the Description of Uniform Circular Motion handout. Using
the information gathered in steps 2 and 3 students can now proceed to the assignment.
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Uniform Circular Motion
Content Material
Student Directions
1.
Read and answer the question in the Worksheet 1 handout.
2.
Access the J-Track Satellite Tracking web site and gather your real world data.
You should download at least 11 data points. Calculate the orbital radius of the
satellite. Record your data and calculations on Worksheet 2.
3.
Use the How Far Is It? web site to calculate the distance traveled by the satellite in
each minute. Calculate the velocity and period of the satellite. Same comment about
Worksheet 2.
4.
Read Description of Uniform Circular Motion handout. After reading the handout,
complete the calculations on Worksheet 2.
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Uniform Circular Motion
Assessment
1. Collect the Worksheet 1 worksheet immediately after it is finished. No grade for
this section.
2. The Worksheet 2 should be started in class. If the students cannot finish the work
in one class period, assign the rest as homework for the next class meeting.
3. The following Assessment of Circular Uniform Motion will provide you with a
possible form of assessment for this project.
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Uniform Circular Motion
Links to Course Competencies
Uniform Circular Motion and Planetary Motion are part of the curriculum of the first
semester of a Physics sequence. This project is designed for the first semester of a twosemester algebra-trig-based college physics course. However by emphasizing the vector
diagrams it could be used in high school courses and one-semester conceptual courses.
Putting more emphasis in the concept of limit and derivatives it could also be used in the
first semester of the calculus-based sequence.
This lesson fits into the PHY 101 College Physics I course taught at Essex County
College. PHY 101 is an algebra-trig based course. It could also be used for calculus
based PHY 103 General Physics I with more emphasis in the concepts of limits and
derivatives.
This RWLO addresses portions of competencies 2, 3 and 4 of the general education
goals:
1. To enable students to become more aware of the different perspectives emanating
from a culturally diverse population.
2. To emphasize critical thinking and problem solving; to the extent possible, to include
quantitative reasoning and research skills, including accessing information from a
variety of sources and media.
3. To enable students to increase proficiency in writing, reading, speaking, and listening
skills.
4. To require students to prepare and present information with the use of computers.
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Uniform Circular Motion
Supplementary Resources
Minds-On Physics Circular Motion: this site contains tutorials in Physics.
http://www.glenbrook.k12.il.us/gbssci/phys/Class/circles/circtoc.html
Science @ NASA: this site contains information about different satellites
http://science.nasa.gov/temp/StationLoc.html
I
Important Facts about Latitude and Longitude (.pdf)
About Longitude and Latitude
Site that allows users to calculate the distance between two points on the Earth’s surface.
How Far Is It?
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Uniform Circular Motion
Recommendations
This project could be used for the first semester any level Physics sequence.
Mathematical expertise will determine what will be emphasized in the analysis.
Back-up:
If the Internet is unavailable, the data provided in the Assessment of Circular Uniform
Motion or in the Back-up Data could be used.
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