Air Resistance and Its Effect on Performance
Air resistance is an external force that opposes motion through the air. In IB Sports, Exercise and Health Science (SEHS), air resistance is used to explain why objects and athletes slow down and why technique and body position are crucial for maximising performance. It plays a particularly important role in high-speed and projectile-based sports.
Air resistance always acts opposite to the direction of motion, reducing speed and altering movement paths.
What Is Air Resistance?
Air resistance, also known as drag, occurs when an object moves through air and collides with air particles. These collisions create a force that opposes motion.
Key characteristics of air resistance include:
- It increases with speed
- It depends on surface area
- It is influenced by shape and body position
In IB SEHS, students should understand that air resistance is not constant and changes depending on movement conditions.
Air Resistance and Speed-Based Sports
Air resistance has a major impact on sports involving high speeds, such as sprinting, cycling, and skiing.
As speed increases:
- Air resistance increases rapidly
- More force is required to maintain speed
- Acceleration becomes harder
This explains why athletes adopt streamlined body positions to reduce drag and improve efficiency.
Air Resistance and Projectile Motion
Air resistance also affects the flight path of projectiles. In real sporting situations, projectiles do not follow perfect parabolic paths due to drag.
Effects of air resistance on projectiles include:
- Reduced range
- Lower maximum height
- Shorter time of flight
In IB SEHS exams, students should recognise that projectile motion is often simplified by ignoring air resistance, but real performance is always influenced by it.
Reducing Air Resistance Through Technique
Athletes use technique and equipment to reduce air resistance and improve performance.
Examples include:
- Cyclists using aerodynamic positions
- Sprinters minimising unnecessary movement
- Skiers wearing tight-fitting suits
Reducing air resistance allows athletes to maintain higher speeds with less energy expenditure.
Air Resistance and Energy Cost
As air resistance increases, the energy cost of movement also increases. Athletes must produce more force to overcome drag, which contributes to fatigue.
This is especially relevant in endurance sports, where inefficient body position can significantly reduce performance over time.
Exam Relevance for IB SEHS
Air resistance questions often require applied explanations. High-mark answers clearly describe how air resistance affects speed, acceleration, or projectile motion and apply these ideas to sporting contexts.
Avoid simply stating that “air slows things down” without explanation.
RevisionDojo Call to Action
If forces like air resistance feel hard to visualise or apply, RevisionDojo helps IB SEHS students master forces and motion with clear explanations and exam-style practice. It is the most effective way to turn abstract concepts into exam-ready understanding.
Frequently Asked Questions (FAQs)
What is air resistance in IB SEHS?
Air resistance is a force that opposes motion when an object moves through air, increasing with speed and surface area.
Why does air resistance matter more at high speeds?
As speed increases, collisions with air particles increase, producing greater opposing force.
How is air resistance tested in IB SEHS exams?
Students are often asked to explain how air resistance affects speed, projectile motion, or performance in specific sports.
