The Pendulum Motion Simulation is an adjustable-size file that displays nicely on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The size of the Interactive can be scaled to fit the device that it is displayed on. The compatibility with iPads, other tablets, and Chromebooks make it a perfect tool for use in a 1:1 classroom. While the use of the Interactive on phones is possible, the high density of controls (sliders, buttons, etc.) does make its use of small screens a bit difficult. If using on a phone, we recommend viewing it in landscape (horizontal) mode.


Teaching Ideas and Suggestions:

This Interactive is intended for use near the early to middle stages of a learning cycle on vibrations and waves. It makes a perfect introduction to periodic motion. The simulation provides real-time output values of the individual force values, the components of the gravity force (tangent to the path and radially), the net force, the acceleration, velocity, and position, and the kinetic and potential energies. A variety of displays are posssible - numerical displays, free-body diagrams (with and without components), position-time plots, velocity-time plots, acceleration-time plots, kinetic energy-time plots, potential energy-time plots, and energy bar charts. 

We present the simulation here as a pendulum motion simulation. It is the default option for the Interactive. But the Interactive can do more than simulate a pendulum. It is a circular motion simulator and can simulate the following scenarios of an object moving in a vertical circle:
  • The motion of a ball suspended from the end of a light string and whirled in a vertical circle (pendulum)
  • The motion of a ball suspended from the end of a light, rigid rod and whirled in a vertical circle
  • The motion of a ball moving along the inside wall of a vertical loop.
  • The motion of a ball rolling down an incline into a vertical loop and continuing along the wall of the loop.
Users can easily toggle between the four instances of moving in a vertical circle and make comparisons between relationships, the direction of forces and accelerations, and the cause-effect relationship between variables. The simulation offers the option of viewing it from the side, from above, or from any angle in between. Force vectors (and their components) can be displayed. Acceleration vectors can be displayed as well. Several sliders allow the user to change the values for parameters associated with the motion and view the impact of such changes immediately. Finally, a numerical output display shows values of the most common motion quantities.

The Physics Classroom has provided the following classroom-ready activity sheets for use by teachers with their classes:
Our Pendulum Motion simulation is now available with a Concept Checker. Do the simulation. Then follow it up with the Concept Checker.


Related Resources

There are numerous resources at The Physics Classroom website that serve as very complementary supports for the Pendulum Motion Simulation. These include:
  • Curriculum/Practice: Several Concept Development worksheets at the Curriculum Corner will be very useful in assisting students in cultivating their understanding of circular motion, most notably ...

    Speed and Velocity
    Acceleration and Circular Motion
    Circular Motion and Inertia
    The Centripetal Force Requirement
    Mathematics of Circular Motion

    Visit the Curriculum Corner.

  • Labwork: 
    Simulations should always support (never supplant) hands-on learning. The Laboratory section of The Physics Classroom website includes several hands-on ideas that complement this Interactive. Two notable lab ideas include ...

    Making the Turn Lab
    Loop-the-Loop Lab

    Visit The Laboratory.
  • Science Reasoning Activities:
    Science classrooms should be filled with reasoning activities. There is one related activity in the Circular Motion section of the Science Reasoning Center and another in the Waves  section. These activities will challenge students to employ close reading, data analysis, and logical reasoning. The activities are ...

    Roller Coaster Loops
    Period of a Pendulum

    Visit the Science Reasoning Center.

Additional resources and ideas for incorporating Pendulum Motion Simulation into an instructional unit can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.


We owe a special thanks to Physics teacher Martin Kirby for donating the Pendulum Motion Simulation to our Interactives collection. If you like this sim, you can tap on the Donate button and buy him a cup of coffee (or a pot of coffee); he'd appreciate it. Martin has contributed many other simulations to our Interactives collection. You can view them all by visiting our page listing all Martin Kirby Simulations. Or visit Martin's website ( to learn more.