Vernier Software and Technology
Vernier Software & Technology

Meet You at the Intersection: Solving a System of Linear Equations

Figure from experiment 30 from Real-World Math Made Easy


Many times, the solution to a real-life problem involves solving more than one mathematical equation at the same time. The simplest situation of this type involves a pair of equations with two unknown quantities called a linear system. Graphically, the solution to this kind of system represents the point where the graphs of these two lines intersect.

For example, imagine that a person is running to catch up to his friend who is walking ahead of him. These motions can be modeled graphically by plotting distance versus time. The motion graphs are linear if each person is moving at a constant speed. If the plots are made on the same set of axes, the point where the two lines cross represents the physical location where the two friends pass each other.

It is possible to model situations of this type in the classroom using two Motion Detectors. In this activity you will collect and analyze motion data in order to determine the solution to a linear system of equations.


  • Record motion data for two walkers.
  • Graph both motions on a common axis and find their intersection.
  • Find linear equations to model the motions.
  • Solve the system of two linear equations to determine the intersection.
  • Compare the algebraic solution to the graphical solution.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Option 1

Option 2

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Standards Correlations

See all standards correlations for Real-World Math Made Easy »

Real-World Math Made Easy

See other experiments from the lab book.

1Walk the Line - Straight Line Distance Graphs
2Making Cents of Math: Linear Relationship between Weight and Quantity
3Pool Plunge - Linear Relationship between Water Depth and Pressure
4Funnel Volumes - Volume and Weight
5Keep It Bottled Up - Rates of Pressure Increase
6Graph It in Pieces: Piecewise Defined Functions
7Mix It Up - Mixing Liquids of Different Temperatures
8Spring Thing - Newton's Second Law
9Stretch It to the Limit - The Linear Force Relation for a Rubber Band
10What Goes Up - Position and Time for a Cart on a Ramp
11That's the Way the Ball Bounces - Height and Time for a Bouncing Ball
12Walk This Way - Definition of Rate
13Velocity Test - Interpreting Graphs
14From Here to There - Applications of the Distance Formula
15Under Pressure - The Inverse Relationship between Pressure and Volume
16Light at A Distance - Distance and Intensity
17Chill Out: How Hot Objects Cool
18Charging Up, Charging Down - Charging a Capacitor
19Bounce Back - The Pattern of Rebound Heights
20Sour Chemistry - The Exponential pH Change
21Stepping to the Greatest Integer: The Greatest Integer Function
22Swinging Ellipses - Plotting an Ellipse
23Crawling Around: Parametric Plots
24Lights Out! - Periodic Phenomena
25Tic, Toc: Pendulum Motion
26Stay Tuned: Sound Waveform Models
27Up And Down: Damped Harmonic Motion
28How Tall? Describing Data with Statistical Plots
29And Now, the Weather - Describing Data with Statistics
30Meet You at the Intersection: Solving a System of Linear Equations
31Titration Curves: An Application of the Logistic Function

Experiment 30 from Real-World Math Made Easy Lab Book

<i>Real-World Math Made Easy</i> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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