Source: https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-8-force-and-extension-springs

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# Force & Extension - Springs

Science Practicals: GCSE, topic 3.1.8

## Hooke's Law - Extending Springs

A force acting on an object may change its size or shape. For example, squashing or twisting an object can change its shape.

### Hooke's Law

![Hooke's Law](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.4.1%20-%20Effects%20of%20forces/sping-min.jpg)

- When a spring is stretched, the increase in the length of the spring is called its “extension”. 
- Hooke’s Law tells us that the extension of a spring is directly proportional to the force applied to the spring:
           force = spring constant x extension.

### Limit of proportionality

![Limit of proportionality](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.4.1%20-%20Effects%20of%20forces/stretched-spring%20-%20Edited-min.jpg)

- Think of the spring constant as the stiffness of the spring. This is different for different objects. 
- The higher the spring constant, the “stiffer” the spring and the more force is needed to stretch it. 
- The limit of proportionality is the point where Hooke’s law breaks down. 
- If a spring is stretched too much, it will not return to its original length when the force stops acting on the spring.

## Test yourself on Force & Extension - Springs

- In the context of springs, what is extension?
- What is the limit of proportionality?
- What do you measure when investigating Hooke's Law?
- Which of the following statements are true according to Hooke's Law and the Limit of Proportionality?
- Which of the following are true about Hooke's law?

[Practise this topic for free](https://app.senecalearning.com/classroom/course/35d9e7b0-1dfb-11e8-b5b7-7546c70e1a36/section/bce31680-1e0c-11e8-b5b7-7546c70e1a36/session)

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## Science Practicals: GCSE contents

### 1 Biology
- 1.1 Practicals
  - [1.1.1 Microscope & Bacteria](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-1-microscope-and-bacteria.md)
  - [1.1.2 Bacteria](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-2-bacteria.md)
  - [1.1.3 Osmosis Tests](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-3-osmosis-tests.md)
  - [1.1.4 Osmosis & Food Tests](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-4-osmosis-and-food-tests.md)
  - [1.1.5 Enzymes](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-5-enzymes.md)
  - [1.1.6 Enzymes 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-6-enzymes-2.md)
  - [1.1.7 Photosynthesis & Plant Responses](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-7-photosynthesis-and-plant-responses.md)
  - [1.1.8 Photosynthesis Experiments](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-8-photosynthesis-experiments.md)
  - [1.1.9 Reaction Time](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-9-reaction-time.md)
  - [1.1.10 Quadrats](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-10-quadrats.md)
  - [1.1.11 Decay](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-11-decay.md)

### 2 Chemistry
- 2.1 Practicals
  - [2.1.1 Salts](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-1-salts.md)
  - [2.1.2 Neutralisation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-2-neutralisation.md)
  - [2.1.3 Titration](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-3-titration.md)
  - [2.1.4 Electrolysis](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-4-electrolysis.md)
  - [2.1.5 Electrolysis 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-5-electrolysis-2.md)
  - [2.1.6 Rate of Reaction](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-6-rate-of-reaction.md)
  - [2.1.7 Rate of Reaction 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-7-rate-of-reaction-2.md)
  - [2.1.8 Chromatography](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-8-chromatography.md)
  - [2.1.9 Identifying Gases](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-9-identifying-gases.md)
  - [2.1.10 Identifying Gases 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-10-identifying-gases-2.md)
  - [2.1.11 Identifying Ions](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-11-identifying-ions.md)
  - [2.1.12 Carbonates, Halides & Sulfates](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-12-carbonates-halides-and-sulfates.md)
  - [2.1.13 Flame Emission Spectroscopy](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-13-flame-emission-spectroscopy.md)
  - [2.1.14 Water Purification](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-14-water-purification.md)
  - [2.1.15 Water Purification 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-15-water-purification-2.md)

### 3 Physics
- 3.1 Practicals
  - [3.1.1 Specific Heat Capacity](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-1-specific-heat-capacity.md)
  - [3.1.2 Thermal Capacity & Insulation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-2-thermal-capacity-and-insulation.md)
  - [3.1.3 Latent Heat](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-3-latent-heat.md)
  - [3.1.4 Resistance & Current](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-4-resistance-and-current.md)
  - [3.1.5 Resistance & Current 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-5-resistance-and-current-2.md)
  - [3.1.6 Density](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-6-density.md)
  - [3.1.7 Density 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-7-density-2.md)
  - [3.1.8 Force & Extension - Springs](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-8-force-and-extension-springs.md)
  - [3.1.9 Waves - Ripple Tank](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-9-waves-ripple-tank.md)
  - [3.1.10 Light](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-10-light.md)
  - [3.1.11 Light Reflection & Refraction](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-11-light-reflection-and-refraction.md)
  - [3.1.12 Radiation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-12-radiation.md)
  - [3.1.13 Radiation 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-13-radiation-2.md)