Unit 10

Which opposing force reduces the motion parallel to the interface of two surfaces in contact?

• Friction

• Newton's third law

• Normal reaction force

• Lift force

Which has the lowest coefficient of friction?

• A football boot turning on wet grass

• A bike tyre rolling on a road

• A beach volleyball bouncing on sand

• A downhill ski moving on snow

Which pair represents the force of friction and normal reaction force in the diagram below?

• Friction: S

  Reaction Force: T

• Friction: T

  Reaction Force: U

• Friction: U

  Reaction Force: T

• Friction: V

  Reaction Force: U

Identify the forces in the picture

• A: Friction

  B: Gravity

• A: Applied Force

  B: Gravity

• A: Drag

  B: Reaction Force

• A: Friction

  B: Applied Force

Identify the forces in the picture

• A: Friction

  B: Gravity

• A: Applied Force

  B: Gravity

• A: Drag

  B: Reaction Force

• A: Friction

  B: Applied Force

Which of these best defines drag?

• The force(s) acting to oppose the motion of an object through a fluid medium such as air or water

• The force(s) acting upon a solid as it moves through air

• The force(s) acting to slow the movement of an object

• The force(s) acting at the surface of a solid in contact with a fluid medium such as air or water

"As a body pushes against a fluid, the fluid pushes back"

Which of the following does this best describe?

• Wave Drag

• Form Drag

• Surface Drag

• Newton's third law

A swimmer wishes to decrease the amount of surface drag acting on them as they swim. Which of the following would best achieve that?

• Wearing a swim cap and smooth body suit

• Swimming in a streamlined position

• Remaining underwater for longer periods

• Using lane ropes

The coefficient of static friction is typically...

• half of the coefficient of dynamic friction

• greater than the coefficient of dynamic friction

• less than the coefficient of dynamic friction

• equal to the coefficient of dynamic friction

The coefficient of friction is calculated by...

• Dividing Frictional force (F) by Applied Force

• Dividing Frictional force (F) by normal force (N)

• Dividing Normal force (N) by frictional force (F)

• Dividing Frictional Force (F) by weight (kg)