Friction Forces Quiz

Which type of friction must be overcome to start moving an object?

• Kinetic friction
• Static friction
• Rolling friction
• Fluid friction

How does the roughness of surfaces affect kinetic friction?

• It decreases friction
• It has no effect
• It increases friction
• It changes the direction of friction

What is the coefficient of kinetic friction?

• A measure of the smoothness of surfaces
• A measure of the roughness between two surfaces
• A measure of the weight of an object
• A measure of the speed of an object

What is the normal force?

• A force that acts parallel to the surface
• A force that acts perpendicular to the surface
• A force that acts in the direction of motion
• A force that acts opposite to gravity

How does the normal force affect friction?

• It decreases friction
• It has no effect
• It increases friction
• It changes the direction of friction

Why is it harder to move a bookcase on carpet than on a wood floor?

• Carpet has a lower coefficient of friction
• Carpet has a higher coefficient of friction
• Wood floor is heavier
• Wood floor is smoother

What is the effect of intermolecular bonds on friction?

• They increase friction
• They decrease friction
• They have no effect
• They change the direction of friction

How does kinetic friction generate heat?

• By increasing speed
• By forming bonds
• By breaking bonds and moving past bumps
• By decreasing speed

What is the role of static friction when an object is at rest?

• To accelerate the object
• To resist motion
• To change the direction of motion
• To increase speed

What happens to static friction when an object starts moving?

• It disappears
• It increases
• It remains constant
• It decreases