Friction Force

Which of the following can affect the friction force between two objects?

• the weight of the objects

• the surface area of contact

• the position of the objects

• the displacement covered by the objects

A frictional force of 200N acts on a block that is moving on a horizontal surface. If the coefficient of friction is 0.20,

then the object's mass is

• 1200 kg

• 102 kg

• 300 kg

• 400 kg

If the normal force is 300N and the friction is 150N, the coefficient of kinetic friction is

• 0.5

• 0.3

• 0.8

• 0.2

Which of the following statements is true?

• The frictional force and the weight are independent of each other

• When the weight of an object increases, the frictional force increases.

• When the weight of an object increases, the frictional force decreases

• When the weight of an object decreases, the frictional force increases.

Which of the following statements is true about motion on a rough surface

• it will be harder for an object to travel over the surface

• there will be a similar motion to a smooth surface

• it will be easier for an object to travel over the surface

• an object will be able to travel faster over the surface

The force that acts in the opposite direction of motion when two surfaces come in contact. 

• Force
• Friction
• Static
• Kinetic 

What direction does friction act relative to motion?

• in the same direction
• in the opposite direction 
• need more information
• depends on the force

Wheels on a skateboard most likely experiences-

• Rolling Friction
• Sliding Friction
• Fluid Friction
• Static Friction

How does friction affect speed?

• more friction decreases speed
• more friction increases speed
• less friction decreases speed

The amount of friction depends on the weight of the objects pressing together.

• True
• False