Friction Quiz

Which type of friction occurs when objects are not moving?

• static
• sliding
• fluid
• rolling

If an object is at rest on an inclined plane, which of the following forces is greatest?

• normal force

• friction

• weight

• Both normal force and weight are equal, so they both are the greatest.

A hockey puck slides on ice at a constant velocity. What is the net force acting on the puck?

• Zero
• Equal to its weight
• Less than its weight but greater than zero
• Depends on the speed of the puck

Tags

NGSS.HS-PS2-1

What is the force of friction between a 950-N block of ice and the horizontal ground if μ = .12?

• 65 N

• 226 N

• 175 N

• 114 N

What is the coefficient of static friction if it takes 44 N of force to move an 86-N box on a horizontal surface?

• 0.78

• 0.51

• 0.78 N

• 0.58 N

A box requires 40 N to start it moving on a horizontal surface when the coefficient of static friction is .54. What is the weight of the box?

• 81 N

• 18 N

• 98 N

• 74 N

A 220-kg crate is pushed horizontally with a force of 700 N. If the coefficient of kinetic friction is 0.20, calculate the acceleration of the crate.

• 1.02 m/s²

• 1.22 m/s²

• 1.42 m/s²

• 1.62 m/s²

Tags

NGSS.HS-PS2-1

If the mass of the block is 20.0 kg, what is the magnitude of F_grav?

• 170 N

• 98.1 N

• 196 N

• 20.0 kg

If the mass of the block is 20.0 kg, what is the magnitude of F_norm?

• 98.1 N

• 170 N

• 196 N

• 17.3 N

How can friction be reduced?

• Reduce the force acting between the two surfaces.

• Reduce the roughness of the two surfaces coming in contact.

• Use wax, grease, or oil.

• All of the above are ways of reducing friction.