Hookes Law

OP6 investigate the relationship between the extension of a spring and the applied force


Investigate the Relationship Between the Extension of a Spiral Spring and the Applied Force

Safety Concerns

Make sure the load is over the base for stability. Take care.


Retort Stand, spring, ruler, masses, calculator, S hook


1/ Suspend a spiral spring from a clamp beside a metre rule.

2/ Measure the length of the unstretched spring, (just the body of the spring, ) this is the 'original length' to be put in the table

3/ The spring and the metre rule must be vertical.

Measure and record the position of the pointer.

4/ Now place a 1 N slotted weight on the hanger – note that the spring stretches.

5/ Measure the new length of the spring & write this into the table.

6/ Repeat steps 4 & 5 adding 1 extra weight each time

Remove the weight and check to see the spring returns to its initial length


Make out a table of data



by subtracting the original position calculate the extension of the spiral spring – record this extension due to a

Graph the results placing force or load (Newtons) on the x-axis and extension (cm) on the y-axis.

Use the graph to calculate the extension that a 3.5 N weight would cause.

Also use the graph to calculate the force needed to produce an extension of 45 cm.

Divide the extension by the load (weight) that caused that extension – the result is approximately the same for each.

/ Observations

what can you say about the points on the graph ?


what can you say about the points on the graph ?

what can you say about the relationship between the force and the extension of an elastic body ?

The extension increases linearly as the load (force) on the spring (band) increases