Friction and Performance in Sport
Friction is an external force that occurs when two surfaces come into contact and move against each other. In IB Sports, Exercise and Health Science (SEHS), friction is used to explain why athletes can grip surfaces, change direction, and control movement, as well as why excessive friction can reduce speed or increase injury risk.
Friction always acts opposite to the direction of motion, either aiding or resisting movement depending on the sporting context.
What Is Friction?
Friction is the force that resists relative motion between two surfaces in contact. In sport, it commonly occurs between:
- Footwear and the ground
- Equipment and hands
- A ball and the playing surface
The amount of friction depends on:
- The nature of the surfaces
- The force pressing the surfaces together
In IB SEHS, students should recognise that friction is not always negative and is often essential for effective performance.
Friction and Movement Control
Friction is critical for movement control. Without sufficient friction, athletes would struggle to start, stop, or change direction.
Examples include:
- A sprinter pushing against the track
- A footballer changing direction quickly
- A gymnast gripping apparatus
Adequate friction allows athletes to apply force effectively to the ground, enabling acceleration and deceleration.
Friction and Speed
While friction is necessary for control, excessive friction can reduce speed. In sports where high speed is the goal, athletes often aim to reduce friction.
Examples include:
- Ice skaters using smooth blades
- Skiers waxing skis to reduce surface resistance
- Cyclists using smooth tyres on road surfaces
Balancing friction is essential: too little reduces control, too much reduces speed.
Friction and Injury Prevention
Friction also plays a role in injury risk. Excessive friction can place stress on joints and tissues, especially during sudden stops or direction changes.
Examples include:
- Knee injuries on high-friction surfaces
- Blisters caused by repeated friction
- Increased joint stress during abrupt deceleration
In IB SEHS, friction is often linked to injury mechanisms and prevention strategies.
Equipment and Surface Design
Sporting equipment and playing surfaces are designed to optimise friction for performance and safety.
Examples include:
- Studs or spikes on footwear
- Textured grips on equipment
- Specialised playing surfaces
These designs aim to provide sufficient traction without increasing injury risk.
Exam Relevance for IB SEHS
Friction questions often require applied explanations. High-mark answers clearly describe how friction affects movement, performance, and injury risk in specific sporting contexts.
Avoid stating that friction is simply “good” or “bad” without explanation.
RevisionDojo Call to Action
If forces like friction feel confusing or difficult to apply in exam questions, RevisionDojo helps IB SEHS students master forces and motion with clear explanations and exam-style practice. It is the most effective way to turn physics concepts into exam-ready understanding.
Frequently Asked Questions (FAQs)
What is friction in IB SEHS?
Friction is a force that resists motion between two surfaces in contact.
Why is friction important in sport?
Friction allows athletes to grip surfaces, apply force, and control movement effectively.
How is friction tested in IB SEHS exams?
Students are often asked to apply friction concepts to sporting movements, surfaces, or injury scenarios.
