Friction and Momentum

What is friction?

• Friction is the force that opposes the relative motion of two surfaces in contact.

• Friction is the attraction between two surfaces that keeps them together.

• Friction is the energy lost due to heat between two surfaces.

• Friction is the force that accelerates two surfaces in contact.

What direction does the friction force act in relation to motion?

• Opposite to the direction of motion

• In a random direction unrelated to motion

• In the same direction as motion

• Perpendicular to the direction of motion

What is the formula for calculating friction force?

• F_friction = N - μ

• F_friction = N / μ

• F_friction = μ + N

• F_friction = μ * N

What does the symbol μ represent?

• Molar mass

• Population mean or micro prefix (10^-6)

• Microorganism

• Standard deviation

What is the difference between static and kinetic friction?

• Static friction is always greater than kinetic friction.

• Kinetic friction only occurs at rest.

• Static friction prevents motion; kinetic friction opposes motion.

• Static friction acts on moving objects.

Which coefficient of friction is generally larger, μs or μk?

• μk is smaller than μs

• μk is larger than μs

• μs is larger than μk

• μs and μk are equal

What does the normal force (N) represent in the friction formula?

• The normal force (N) is the force of gravity acting on an object.

• The normal force (N) is the total force acting on an object in motion.

• The normal force (N) is the frictional force opposing motion.

• The normal force (N) represents the perpendicular force exerted by a surface on an object.

What happens to the friction force if the normal force increases?

• The friction force increases.

• The friction force decreases.

• The friction force remains the same.

• The friction force becomes zero.

What type of friction occurs when surfaces are not moving relative to each other?

• Static friction

• Fluid friction

• Kinetic friction

• Rolling friction

What type of friction occurs when surfaces are sliding against each other?

• Kinetic friction

• Fluid friction

• Rolling friction

• Static friction