Pasco Fan Cart with Motion Detector

PIRA 1C20.33

The Pasco Fan Cart is designed to move with little friction on the Pasco Dynamics Track. The fan provides a constant force, and a constant acceleration. The cart has two fan speeds, and the angle of the fan post can be adjusted. By adjusting the fan speed and the fan post angle, a wide range of linear accelerations are available. The motion detector allows simultaneous, real-time measurements of position, velocity, and acceleration as functions of time. This requires the Pasco 750 Interface, and a computer with Pasco Science Workshop software.

Demonstrate the motion of the fan cart without the motion detector for a specific initial velocity and constant acceleration. Have students sketch graphs predicting the position, velocity, and acceleration for that motion. A classic example is to give the fan cart an initial velocity away from the motion detector, with the fan accelerating the cart towards the motion detector. Repeat the demonstration with the motion detector on, and the real-time position, velocity, and acceleration graphs projected onto a screen with an LCD projector connected to the computer.

The motion detector cannot register an object closer than about 20 cm, so the fan cart must be placed at least 20 cm from the end of the dynamics track. With careful allignment of the motion detector, the motion of the fan cart can be picked up over the entire length of the 2 m dynamics track. This allignment can be tricky, so allow plenty of time prior to class for adjustments.