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Chapter 5 · Forces and Matter — Lesson 5.3
Hooke's Law: Spring Lab
Drag the load and watch the spring respond live, with its initial length, extension, and new length marked directly on it. Push it past the elastic limit and it won't spring all the way back. Compare stiffness settings to see how much less a stiffer spring stretches for the same load.
Live Spring & GraphAt rest
0.0 cm
40 N/m
Readouts
Force applied
0.00 N
Initial length L₀
10.0 cm
Extension Δx
0.0 cm
New length L
10.0 cm
Spring constant k
40 N/m
Reading the Curve
Hooke’s law region: straight line through the origin. F = kx.
Limit of proportionality: the line stops being straight here.
Elastic limit: beyond this, the spring won’t return to its original length once unloaded. The dashed line shows its new, permanent path.
F = k x
true only in the Hooke’s law region, up to the limit of proportionality
What Each Variable Means
F
Force (load)
The pulling force applied to the spring, in newtons (N).
x
Extension
How much longer the spring gets compared to its natural length, in cm.
k
Spring constant
k = F/x, but only up to the limit of proportionality. A bigger k means a steeper line — more force needed for the same stretch.