Even if you've never played with a spring before, you've definitely used something that has a spring inside: a mattress, a watch, a retractable pen, a scale, or maybe a door that closes on its own. All of these things rely on a spring force to function.

The spring force is pretty simple: if you pull the ends of a spring apart the spring gets longer, and if you push the ends of a spring together the spring gets shorter. And we know from Newton's 3rd law that if you pull or push a spring, the spring pulls or pushes you back with the same force.

In this lesson we'll cover Hooke's law which relates the spring force and the amount that the spring changes length, which depends on the spring constant (which describes the stiffness of the spring). We're only going to work with what we call "ideal springs", which means the spring force varies linearly with the change in length.

We'll also learn about combining springs in series and in parallel to get an "equivalent spring constant".

Finally, we'll learn how this spring-like behavior applies to the elasticity of materials. A rubber band is one example, but it turns out that everything stretches when you apply a force to it - every material actually behaves like a spring.

Multiple-Choice Questions

Answers

- Spring Force

• Flipping Physics - Hooke's Law Introduction - Force of a Spring
• Matt Anderson - Horizontal vs vertical springs
• Equivalent Springs in Series and Parallel

- Elasticity of Materials

• Khan Academy - Elastic and non elastic materials
• Organic Chemistry Tutor - Elasticity & Hooke's Law

• Michel van Biezen - Spring and Weight
• Matt Anderson - How to determine the spring constant
• Organic Chemistry Tutor - Stress and Strain - Elastic Modulus

• The Efficient Engineer - Understanding Young's Modulus

Other Resources

Even if you've never played with a spring before, you've definitely used something that has a spring inside: a mattress, a watch, a retractable pen, a scale, or maybe a door that closes on its own. All of these things rely on a spring force to function.

The spring force is pretty simple: if you pull the ends of a spring apart the spring gets longer, and if you push the ends of a spring together the spring gets shorter. And we know from Newton's 3rd law that if you pull or push a spring, the spring pulls or pushes you back with the same force.

In this lesson we'll cover Hooke's law which relates the spring force and the amount that the spring changes length, which depends on the spring constant (which describes the stiffness of the spring). We're only going to work with what we call "ideal springs", which means the spring force varies linearly with the change in length.

We'll also learn about combining springs in series and in parallel to get an "equivalent spring constant".

Finally, we'll learn how this spring-like behavior applies to the elasticity of materials. A rubber band is one example, but it turns out that everything stretches when you apply a force to it - every material actually behaves like a spring.