Hooke's Law Lab
Investigate how a spring stretches under load. Hang masses, measure the extension, and discover the linear relationship between force and extension. Plot F vs x to find the spring constant from the slope, then explore how elastic potential energy scales with extension.
Guided Experiment: Hooke's Law Investigation
If you increase the hanging mass on a spring, what do you predict will happen to the extension? Will the relationship be linear?
Write your hypothesis in the Lab Report panel, then click Next.
Controls
Results
Force vs Extension
Data Table
(0 rows)| # | Trial | Mass(kg) | Force(N) | Extension(m) | Elastic PE(J) |
|---|
Reference Guide
Hooke's Law
A spring exerts a restoring force proportional to its extension from the natural length.
Where F is the spring force (N), k is the spring constant (N/m), and x is the extension (m). The relationship holds only within the elastic limit.
Spring Constant
The spring constant k measures stiffness. A larger k means a stiffer spring that stretches less for the same force.
Plot F on the y-axis and x on the x-axis. The slope of the straight line through the origin equals the spring constant.
Elastic Potential Energy
A stretched spring stores energy. Because force increases linearly with extension, the stored energy is the area under the F vs x graph — a triangle.
Doubling the extension quadruples the stored energy. This energy is released when the spring returns to its natural length.
Limitations
Hooke's Law applies only within the elastic limit. Beyond this point the spring undergoes permanent (plastic) deformation and F is no longer proportional to x.
The elastic limit varies by material. Steel springs have a large elastic range; rubber bands do not follow Hooke's Law at all — their F vs x graph is non-linear.
In this lab, all extensions are assumed to be within the elastic limit. In a real experiment you would check by removing the load and verifying the spring returns to its original length.