With a wireless motion detector, you can easily explore relative velocities, allowing students to confirm the validity of the Galilean transformation at non-relativistic speeds in the classroom. Combining the Go Direct Sensor Carts with the Go Direct Motion Detector makes this type of experiment possible.
Try a short relative velocity experiment using two Go Direct Sensor Carts, each measuring its own position relative to a track, and a Go Direct Motion Detector mounted on one of the carts to measure its position relative to the other cart.
In this example, two carts are pushed in the same direction but with different initial speeds. The velocity vs. time graph clearly shows the velocity of the front cart (Velocity Y, in green) relative to the track, the velocity of the trailing cart (Velocity G, in blue) relative to the track, and the Velocity (in Red) of the front cart relative to the trailing cart. As displayed in the graph traces, the red trace always shows the difference between the green trace and blue trace velocities.