PBR011525FRIC2

What is the formula to calculate the frictional force when the normal force and the coefficient of friction are known?

Which of the following factors does NOT affect the magnitude of friction between two surfaces?

• The roughness of the surfaces

• The area of contact between the surfaces

• The normal force acting on the surfaces

• The type of materials in contact

A block is at rest on an inclined plane. As the angle of the incline increases, the block begins to slide. Which type of friction is initially acting on the block, and what type of friction acts once it starts sliding?

• Static friction initially, then kinetic friction

• Kinetic friction initially, then static friction

• Only static friction throughout

• Only kinetic friction throughout

A car is moving on a road. Explain how friction is beneficial in this scenario and what would happen if friction were absent.

• Friction allows the car to move forward and stop; without it, the car would not be able to start or stop effectively.

• Friction causes the car to slow down; without it, the car would move faster.

• Friction is not involved in the car's movement; without it, nothing would change.

• Friction only affects the car's tires; without it, the tires would wear out faster.

Tags

NGSS.MS-PS2-2

A 10 kg box is placed on a horizontal surface with a coefficient of static friction of 0.4 and a coefficient of kinetic friction of 0.3. Calculate the minimum force required to start moving the box.

• 30 N

• 40 N

• 50 N

• 60 N

Tags

NGSS.MS-PS2-2