Friction | MCQs

Explanation

Limiting frictional force (also known as static friction) is greater than:

• Rolling friction (because rolling friction is much smaller, as it only opposes the motion of an object that is already rolling)
• Sliding friction (which is another term for kinetic friction)
• Kinetic friction (which is the frictional force that acts when an object is already moving)

Explanation

• Friction is a force that opposes motion between two bodies in contact, and it arises due to the interaction between the surfaces in contact.
• The roughness of the surfaces, including microscopic imperfections and irregularities, leads to interlocking and resistance to motion.
• This resistance is what we experience as friction.

Explanation

When two surfaces slide over one another the tiny bumps push on each other.

Friction causes a force on a surface that is in the opposite direction to its motion.

Friction can be reduced by the application of lubricants

ND20-1-2023

Explanation

The force of friction opposes the motion of an object, causing moving objects to lose energy and slow down.

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ND18-1-2023

Explanation

Frictional unemployment often occurs when people first enter the labor force.

Explanation

• When the child rubs the balloons with wool, the balloons become statically charged with the same type of charge (either positive or negative).
• When two objects with the same charge are brought near each other, they repel each other.

Explanation

• When you run a plastic comb through your dry and non-oily hair, the comb becomes statically charged.
• This static charge causes the comb to attract small, light objects like bits of paper.
• When you hold the comb above the paper, the paper is attracted to the comb due to the electrostatic force.

Explanation

• Swimmers make their bodies streamlined to reduce friction underwater.
• It allowing them to move more efficiently and quickly through the water.

Explanation

• Friction forces between the air and a moving object cause resistance.
• Which slows down the object and converts some of its kinetic energy into heat.

Explanation

• Grease is a lubricant that can be used to reduce friction between moving parts of machines.
• It helps to reduce wear and tear, prevent overheating, and allow parts to move smoothly.