1. All levels
  2. UK GCSE (Age 14-16)
  3. UK A-level (Age 16-18)
  4. UK Higher Ed. (Age 18+)

Materials Materials

Hooke's Law

Hooke's law describes how springs respond to having forces applied. This experiment allows you to apply force using weights and measure how springs of different stiffness extend in response. You can calculate the stored elastic potential energy in the springs and even go to different parts of the Solar System to see how changing the strength of gravity changes the weight applied to the springs!

Press GO to launch the experiment!

Stretching – the truth!

You may wonder why we study springs and why questions about stretching springs appear on exams. Sure, springs are used in the world, but are they really so important? Why is it important to know how springs stretch when they are pulled?

Well, first, springs are incredibly useful. When made from elastic materials, such as most metals, springs stretch when pulled and return to their original size when released. They can also be compressed and, again, return to their original size when released. The stretching or compression stores energy that is then returned when the spring is released. This energy storage and return is the key reason springs are useful. Springs use this capability in all sorts of applications, including in high tech areas such as automotive, industrial tools and robotics, to more everyday items such as trampolines, mattresses, children’s play equipment, door handles and retractable pens. 

The second reason is that the way that springs respond to force being applied to them (i.e. being pulled or mass added to one end of them) is identical to how materials in general behave. If materials are pulled, then they stretch. The coiled shape of a spring, though, means that the ends tend to move large distances compared to a regular shape of the same material (e.g. a simple rod). This means that studying what happens to springs when they are pulled allows simple measurements to be performed that give us understanding of how all materials behave when they are pulled. Materials behave this way in any application where they have force applied to them, e.g. in construction, vehicles, heart valves, body implants, plants, rocks, furniture, tools, footwear – the list goes on and on. And don’t forget this includes your body too!

Use this experiment to find out more!