Carousel Video Clips

See the fun!

Download the video clips! Right-click on the links below to see the videos of motion seen both inside a rotating frame of reference (playground carousel) and viewed externally, from an approximately inertial frame (the ground).

Coriolis (260 kB)

This clip shows the trajectory of a tennis ball tossed right at the camera apparently curving under the influence of the Coriolis force.

Coriolis from the ground (695 kB)

This clip shows the trajectory of a tennis ball in a game of catch on the carousel, but from the perspective of the camera on solid ground. Although the trajectories are difficult for the players on the carousel to follow, from the ground they appear perfectly normal.

Foucault’s Pendulum (2.4 MB)

This clip follows a pendulum freely swinging from a rotating carousel, observed from the rotating frame of the carousel. The direction the pendulum swings apparently rotates in synchrony with the rotation of the carousel. Shown for two revolutions of the carousel.

Juggler (834 kB)

This clip is just for fun. A juggler gamely tries to juggle while riding on a rotating carousel — and actually succeeds for a little while.

Angular Momentum (1.9 MB)

This clip shows the carousel’s angular velocity changing even though no torque is applied to it. When riders move toward the center of the spinning carousel, it spins faster. When they move back away from the center, the carousel slows down. This is because the carousel’s angular momentum stays constant as its rotational inertia (moment of inertia) changes. Note that one of the riders loses a shoe.

Note: If you left-click the links, your browser may play the files, but it may not. It depends on what add-ins it has installed. If you right-click on the links, you can directly download the files and play them with whatever player you have that works. These are MOV files, which will work with QuickTime. I cannot guarantee that they will work with any other application.