Physics 303 Review-Friction

Front

What direction does kinetic friction point?

Back

Kinetic friction points parallel to the points of contact, opposite each object's relative motion.

Front

What is a macro-form of friction where asperities from one material are broken off by the other material, creating a frictional force on both?

Back

Surface Roughness is a macro-form of friction where asperities from one material are broken off by the other material.

Front

Which force is represented by the arrows in a free body diagram?

Back

Air Resistance is represented by the arrows in a free body diagram.

Front

What is a form of friction where the harder of the two materials pushes the softer material out in front of itself, causing a frictional force?

Back

The Plowing Effect is a form of friction where the harder material pushes the softer material out.

Front

What is the coefficient of static friction if it takes 44 N of force to slightly move a box that weighs 86 N?

Back

The coefficient of static friction is 0.51.

Front

Define kinetic friction.

Back

Kinetic friction is the force that opposes the motion of two surfaces sliding past each other.

Front

What is the difference between static and kinetic friction?

Back

Static friction prevents motion between two surfaces, while kinetic friction acts when the surfaces are sliding past each other.

Front

What factors affect the coefficient of friction?

Back

The coefficient of friction is affected by the materials in contact and the surface roughness.

Front

Explain the term 'normal force'.

Back

Normal force is the perpendicular force exerted by a surface to support the weight of an object resting on it.

Front

What is the role of surface roughness in friction?

Back

Surface roughness increases the contact area between two surfaces, which can increase friction.