Setup

Location

In order to measure gravity with 1/10,000 accuracy we had to find a location that would allow to measure a fairly long pendulum. We chose the stairwell due to its 3 and a half story height and railings that allowed for ease of setting up a stable pendulum with the clamps we had access to.

Pendulum

In order to measure gravity using a simple pendulum we hung the pendulum in the stairwell. At the top of the pendulum a fishing line was hung from a screw eye that was screwed into a clamp compatible with it. The clamp was then attached to a plank of wood that was also clamped to the railing on the stairwell between the third and fourth floors. In order to protect the wall from any damage that could occur, and to stabilize our hanging rig, we put a rubber pad between the wall and the plank of wood. This can be seen in the image. At the bottom of the stairwell we attached a 769.30 g mass to the end of the fishing wire to complete the pendulum.

Timing

A photo-gate was used to accurately measure the period once the pendulum was set to swing. The photo-gate was positioned so that every time the pendulum swung it would pass through. The photo-gate was then connected to a Science Workshop 500 which served as an intermediary to the computer. When connected to the computer the timing was set up through PASCO Capstone which automatically would give the period of the pendulum within about a hundredth of a second. At the end of taking data, the Capstone software had a feature to export all data to a text file which was used when moving on to data analysis.