1. Measuring Force:

• Measure the mass of each object (mass in kg) and calculate its weight, which is the force applied to the spring, using the formula:

• W = weight (force) in newtons (N)
• m = mass in kilograms (kg)
• g = gravitational field strength (9.8 N/kg on Earth)

Optional Pilot Experiment

Before conducting the full experiment, you may want to perform a pilot test to determine the best size of masses to use:

1. Use a similar spring to the one being tested.
2. Add masses one at a time and record both the force (weight) and the extension.
3. Plot a force-extension graph. The graph should show a straight line at least for the initial points, which indicates the relationship is proportional.
4. If the graph curves too early, it means you're using masses that are too large. Reduce the size of the masses to stay within the limit of proportionality.

The force causing this extension is due to the gravitational force acting on the masses, and the extension follows Hooke's Law:

• F = force (N)
• k = spring constant (N/m)
• x = extension (m)

Steps for the Main Experiment

1. Measure the Natural Length of the Spring:

• Without any load, measure the spring's natural length using a millimetre ruler. Clamp the ruler to a stand and ensure the measurement is taken at eye level for accuracy.
• Attach markers (thin strips of tape) to the top and bottom of the spring for clear readings.

2. Add Masses:

• Gradually add masses to the spring, allowing the spring to come to rest after each addition.
• Measure the new length of the spring after each mass is added. The extension is the difference between the new length and the natural length.

3. Record Data:

• Record the weight (force) and corresponding extension for each mass.

4. Repeat:

• Continue adding masses until you have collected at least 6 or more data points for reliable results.

5. Plot the Force-Extension Graph:

• Plot the data on a graph with force on the y-axis and extension on the x-axis.
• The graph should show a straight line if Hooke's Law is obeyed. It will start to curve once the spring's limit of proportionality is exceeded.