Question

Which among the following helps to reduce the friction between two surfaces?

• A. Grooves
• B. Polishing
• C. Lubricants
• D. Ball bearings

Answer 1

Answer: (B), (C), (D)

The correct options are
B Polishing
C Lubricants
D Ball bearings

Polishing, usage of lubricants and ball bearings are the major effective methods for reducing the friction between two surfaces. Polishing helps to reduce the interlocking between the surfaces. Ball bearings are used in machines because when metal balls are placed between two sliding surfaces, they replace the sliding friction to rolling friction. Usage of lubricants fills the gap between two sliding surfaces, hence reduces friction.
Grooves on tyres or shoes help in increasing the friction for a better grip.