What are the three main types of friction?

• Kinetic friction, viscous friction, thermal friction

• Static friction, fluid friction, magnetic friction

• Frictionless motion, sliding friction, air resistance

• Static friction, kinetic friction, rolling friction

How does surface roughness affect friction?

• Surface roughness has no effect on friction.

• Smoother surfaces always result in higher friction.

• Increased surface roughness decreases friction.

• Surface roughness generally increases friction due to enhanced interlocking of surface features.

Can you give an example of static friction in everyday life?

• A person pushing a heavy box across the floor.

• A book resting on a table.

• A ball rolling down a hill.

• A car sliding on ice.

What role does weight play in the amount of friction?

• Weight has no effect on friction.

• Increased weight decreases friction.

• Weight increases the amount of friction.

• Friction is only dependent on surface texture.

How is friction beneficial in sports?

• Friction is beneficial in sports as it enhances grip and control, enabling better performance and safety.

• Friction reduces speed and control in sports.

• Friction is only harmful and has no benefits in sports.

• Friction makes surfaces slippery, which is advantageous for athletes.

What is kinetic friction and how does it differ from static friction?

• Kinetic friction only acts on rough surfaces.

• Static friction occurs between moving surfaces.

• Kinetic friction is stronger than static friction.

• Kinetic friction opposes motion between sliding surfaces, while static friction prevents motion between stationary surfaces.

Name a common application of friction in machinery.

• Braking systems

• Lubrication systems

• Power transmission systems

• Cooling systems

What techniques can be used to reduce friction in engines?

• Reducing engine size

• Using water as a coolant

• Increasing engine temperature

• Techniques to reduce friction in engines include using lubricants, improving surface finishes, utilizing low-friction materials, and implementing advanced design features.

How does temperature influence friction between surfaces?

• Temperature has no effect on friction.

• Temperature influences friction by changing material properties and affecting lubrication.

• Higher temperatures always increase friction.

• Friction is solely determined by surface roughness.

Why is friction important for walking or running?

• Friction increases speed but makes running harder.

• Friction is essential for walking or running as it prevents slipping and allows for effective propulsion.

• Friction is only important for climbing steep surfaces.

• Friction helps in maintaining body temperature while exercising.