In this blog, we’re going to look at levers and the concept of mechanical advantage — both are important topics for your GCSE PE exams. Let’s make this easy to understand so you can feel confident tackling any questions on this topic that might come up in your exams.
What Is Mechanical Advantage?
Mechanical advantage is the ability of a lever system to move a large load with a small amount of effort.
This happens because the effort is further away from the fulcrum (the pivot point) than the load is. In simpler terms, it’s about how much easier it becomes to lift or move something using a lever system.
The Lever System
Levers in the body are made up of three parts:
- Fulcrum: the pivot point (e.g., your joints).
- Load (Resistance): the weight or resistance you want to move.
- Effort: the force applied to move the load (usually your muscles). A simple way to remember which component of a lever is found in the middle of each class of lever is by using this short phrase: “FLE 1-2-3”. This stands for Fulcrum, Load, and Effort and tells you which component is in the middle for each lever class.
The Three Classes of Levers
1. First-Class Lever
- The fulcrum is in the middle.
- Sporting examples: The movement of your head when heading a football. The extension of the elbow in a thrown-in in football.
- FLE: The fulcrum is in the middle of a 1st class lever.
2. Second-Class Lever
- The load is in the middle.
- Sporting example: A basketball player standing on their toes preparing to shoot.
- FLE: The load is in the middle of a 2nd class lever.
3. Third-Class Lever
- The effort is in the middle.
- Sporting example: Flexion of he elbow duirng the upward phase of a biceps curl
- FLE: The effort is in the middle of a 3rd class lever.
Effort Arm vs Resistance Arm
You might well be asked to draw and label a lever system in your exam, it’s important to identify the effort arm and the resistance arm:
- The effort arm is the distance from the fulcrum to where the effort is applied.
- The resistance arm is the distance from the fulcrum to where the load (or resistance) is placed.
As shown in this image
Calculating Mechanical Advantage
To calculate mechanical advantage, use the following formula:
Mechanical Advantage = Effort Arm divided by Resistance Arm
Just remember, you divide the effort arm by the resistance arm.
High vs Low Mechanical Advantage
- High Mechanical Advantage: This occurs when the effort arm is longer than the resistance arm, making it easier to move the load.
Example: A second-class lever (like standing on your toes) has a high mechanical advantage because the effort (your calf muscles) is further away from the fulcrum (the ball of your foot) than the load (your body weight). - Low Mechanical Advantage: This occurs when the effort arm is shorter than the resistance arm, meaning it’s harder to move the load.
Example: A third-class lever (like a bicep curl) has a low mechanical advantage because the effort (your bicep) is closer to the fulcrum (your elbow) than the load (the weight in your hand).
Let’s Test Your Knowledge
Can you identify the mechanical advantage?
- First-Class Lever: The fulcrum is in the middle, with the effort arm longer than the resistance arm.
- High or low mechanical advantage?
Answer: High—because the effort arm is longer than the resistance arm.
- Third-Class Lever: The effort is in the middle, with the resistance arm longer than the effort arm.
- High or low mechanical advantage?
Answer: Low—because the effort arm is shorter than the resistance arm.
Levers and mechanical advantage might seem a bit tricky at first, but by breaking it down into simple steps, it’s possible to master this concept. Remember the “FLE 1-2-3” rule, how to calculate mechanical advantage, and the differences between high and low mechanical advantage.
Keep practising, and you’ll be able to answer questions on levers and mechanical advantage with confidence!
Good luck with your revision and exams!
For more support with your GCSE revision and exam preparation, you might like to enrol on my online revision course here.
