Tyres are treaded to?

Analysis

The question asks for the physical purpose of the patterns (treads) carved into the surface of vehicle tyres.

Concept Explanation

In physics, friction is the force that opposes the relative motion between two surfaces in contact. For a vehicle to move, stop, or turn safely, there must be sufficient friction between the tyre and the road surface.

• Smooth surfaces: When a tyre is smooth (bald), there is very little grip, especially on wet roads. Water can form a thin film between the tyre and the road, causing the vehicle to "hydroplane" or skid.
• Treaded surfaces: Treads are the grooves cut into the tyre. They serve two main purposes: • Channeling water: They act as drainage channels to push water away from the contact patch, allowing the rubber to maintain direct contact with the road. • Increasing grip: The edges of the tread patterns dig into the road surface (especially on loose surfaces like gravel or mud), which significantly increases the coefficient of friction between the tyre and the road.

Step-by-Step Solution

1. Evaluate Option A: Increasing the weight of the tyre is not a goal; in fact, manufacturers try to keep tyres as light as possible to improve fuel efficiency.
2. Evaluate Option B: Treads create a rougher surface profile. By increasing the surface area contact and providing a path for debris/water to escape, the tyre gains a better "grip" on the road. This grip is the physical manifestation of increased friction.
3. Evaluate Option C: While treads wear down over time, the primary purpose of the design is safety (friction), not necessarily to make the tyre last longer.
4. Evaluate Option D: Aesthetics are a secondary consideration for manufacturers, but it is not the scientific reason for the existence of treads.

Conclusion

Treads are essential for safety because they ensure the vehicle can maintain traction. By increasing the grip on the road, they increase the frictional force available for braking and steering.

Exam Tip

Whenever you see a question about "treads," "spikes on shoes," or "grooves on soles," always associate them with increasing friction. Conversely, if a question asks how to reduce friction, look for answers involving "lubrication," "ball bearings," or "streamlining."