Question

Which of the following is a way to increase friction between two surfaces?

• A. Using ball bearings
• B. Using lubricant between the surfaces
• C. Making the surfaces rough
• D. Polishing the surfaces

Answer 1

The correct option is C

Making the surfaces rough

When a body is placed on the other body, the irregularities of the two surfaces get interlocked. Friction comes into action as we try to overcome the interlocking of these irregularities.
Making the surface rough, increases the irregularities which in turn increases friction.
Ball bearings convert sliding friction to rolling friction which is less than sliding friction. By using methods like polishing and lubrication irregularities on a surface gets reduced and hence friction decreases.