Static Friction and Inclined Planes

The video tutorial explains static friction, which prevents a box on an inclined plane from sliding down. It describes how static friction acts at the contact surface, generating a force that opposes motion. The tutorial covers the concept of force equilibrium and how increasing force can overcome static friction, leading to motion. It introduces the static friction coefficient, which depends on the materials in contact, and provides an example calculation for a wooden box on a wooden surface.

What prevents a box from sliding down an inclined plane?

• Static friction

• Gravity

• Air resistance

• Kinetic energy

What happens to the static friction force as you increase the force applied to the box?

• It decreases

• It remains constant

• It increases

• It becomes zero

When does the box start to slide down the inclined plane?

• When the applied force equals the static friction force

• When the applied force is less than the static friction force

• When the applied force exceeds the static friction force

• When the normal force is zero

What is the relationship between the maximum static friction force and the normal force?

• They are equal

• They are unrelated

• They are directly proportional

• They are inversely proportional

What does the static friction coefficient depend on?

• The materials of the box and surface

• The angle of the inclined plane

• The speed of the box

• The weight of the box

Which material combination has a static friction coefficient of 0.2?

• Wood on wood

• Steel on steel

• Stone on wood

• Plastic on metal

What is the static friction coefficient for wood on wood?

• 1.0

• 0.5

• 0.2

• 0.9

How do you calculate the static friction force for a box on a surface?

• Divide the normal force by the static friction coefficient

• Multiply the static friction coefficient by the normal force

• Add the mass and the gravitational acceleration

• Multiply the mass by the gravitational acceleration

What is the normal force equal to for a box on a horizontal surface?

• The static friction force

• The applied force

• The kinetic friction force

• The gravitational force

How much force is needed to set a 10 kg wooden box in motion on a wooden surface?

• 9.8 Newtons

• 49 Newtons

• 98 Newtons

• 5 Newtons