A half-Atwood machine, with a cart, string, pulley, and hanging mass, is a common Newton’s Second Law and kinematics lab. If you have a pulley and photogate in this setup, you can easily collect position, velocity, and acceleration data. Setting up the photogate to intercept the pulley spokes can be accomplished two ways:

1) The Photogate Bracket (PGB-VDS) has two sides with different tabs. One side is configured for a vertical position for supporting a photogate over the track surface. The other side has tabs for a 45 degree position.

It is this position that allows you to easily support a photogate so that it can read the motion of a pulley.

This image shows how to configure the bracket.


2) Starting in 2016, the Pulley Bracket (B-SPA) includes a special attachment for photogates.

This image shows how to configure the bracket.