Vernier Software and Technology
Vernier Software & Technology

Demon Drop: A Mathematical Modeling Activity


Demon Drop is a popular ride at Dorney Park & Wildwater Kingdom in Pennsylvania. During the ride, four people in a cage are in vertical freefall for a short time. Then they ride along a curved track and are finally brought to a stop while riding along on a straight level segment of track.

Newton’s Law of Gravitation tells us that the Earth exerts a constant force on an object that is close to its surface. If no other forces are present, Newton’s Second Law of Motion can be used in conjunction with data about the Earth’s mass and radius to predict that an object falling freely near its surface will undergo a constant downward acceleration of magnitude 9.8 m/s2. Is this really the acceleration of the cage full of people? To answer this question you’ll analyze a video of the of the cage’s fall.


In this activity, you will

  • Predict what kinematic equation will describe the vertical motion of the cage.
  • Obtain height vs. time data from the video.
  • Develop an analytic mathematical model, which is an equation that describes the details of the cage’s motion.
  • Compare the model to the data.

Software for Experiment

This experiment uses Logger Pro software for video analysis. The video for analysis is included with the lab book.

Download Complete Experiment

The downloadable file contains the student instructions in PDF and Word format as well as the teacher information.

Download Experiment

Physics with Video Analysis

See other experiments from the lab book.

1Rolling Ball
2Big and Small: How to Scale an Image
3Velocity Change
4Velocity and Speed
5Velocity and Acceleration
6Three Movies: Determining Constant Acceleration
7Demon Drop: A Mathematical Modeling Activity
8Jumping on the Moon
92D Vectors: Pool Ball Displacement, Velocity, and Speed
10Galileo's Projectile I: Using 17th Century Techniques
11Galileo's Projectile II: Using Contemporary Techniques
12Projectile Motion Vectors
13Frictional Slowing
14Impulsive Juggling
15Center of Mass Motions
16Finding a Spring Constant
17Net Work - Kinetic Energy Theorem
19Slinky Wave Speeds
20Superposition of Slinky Waves
21A Wave Pulse Equation
22Doppler Effect: Surface Water Waves
23Doppler Effect: Sound Waves
24A Heat Engine: Relating Work to the P-V Cycle
25Coulomb's Law for Two Charged Spheres
26Discharge Rate
27Electric Field Due to a Line of Charge
28Resistance and Ohm's Law
29Parallel Plate Capacitor: Potential Difference vs. Spacing
30Wiring Capacitors in Series and Parallel
31Using RC Decay to Determine Capacitance
32Exploring Faraday's Law
33Snell's Law of Refraction

Experiment 7 from Physics with Video Analysis Lab Book

<em>Physics with Video Analysis</em> 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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