Search for Science Fair Projects

1000 Science Fair Projects with Complete Instructions

Forces and Motion Science Fair Project

Gravitational Attraction with an Ancient-Style Torsion Balance

Hard
Gravitational Attraction with an Ancient-Style Torsion Balance | Science Fair Projects | STEM Projects
Can you measure the tiny gravitational pull between two objects using only materials available in ancient times? A torsion balance detects this force by letting a suspended beam twist toward nearby masses. You build a balance arm from a thin pine strip with lead weights at each end. Vegetable fibre from twine suspends the beam. Two large stone test masses (paving stones) are placed near the lead weights. The gravitational pull between the stones and lead causes the beam to twist slightly. The challenge is the support fibre. Natural fibres respond to humidity and tear under stress. Selecting and preparing the right fibre takes patience and repeated testing.

Hypothesis

The hypothesis is that the gravitational force between two masses can be measured using Archimedes' Apparatus.

Method & Materials

You will use a balance arm, cradle, and support fibre to measure the gravitational force between two masses.
You will need a strip of pine wood, lead or gold weights, twine, and vegetable fibre.

MEL Physicshands-on physics experiment kits delivered monthly — real experiments, not just reading. (Affiliate link)

See whats included

Results

This experiment shows that the gravitational force between two masses can be measured using Archimedes' Apparatus. The most difficult component to replace with a 3rd century B.C. analogue was the support fibre, which required experimenting with a variety of alternatives and compromising with the shortcomings of whatever was selected.

Why do this project?

This science project is unique because it uses materials available in antiquity to measure the gravitational force between two masses.

Also Consider

Experiment variations to consider include using different materials for the balance arm and cradle, and using different test masses.

Full project details

Additional information and source material for this project are available below.

Related video

These videos explain the science behind this project and demonstrate key concepts used in the experiment.
Share this Science Project:

Related Science Fair Project Ideas

Boat Bow Shape and Water Drag
Build three wooden boats with different bow shapes and measure which one creates the least drag in flowing water.
Hard
Javelin Release Angle and Distance
Film trained athletes throwing javelins at six different angles to discover which release angle produces the longest throw.
Hard
Bat Material and Ball Bounce at Equal Swing Speed
Mount a bat on a stand and fire baseballs at it to test whether material matters without a batter.
Hard
Share this Science Project: