Answer:
Step-by-step explanation:
1. Use of lubricants
Lubricants like oil and grease helps to decrease friction by forming a thin film in between different parts of the machine. This film covers up the scratches and bumps on the surfaces of different parts. This reduces interlocking between the two surfaces. Thus reducing the friction.
2. Use ball bearings
Two moving surfaces in a machine are attached by placing small steel balls or steel rollers in between them. This way, the moving parts avoid direct contact and the force of sliding friction turns into rolling friction. Rolling friction is less than sliding friction, in doing so reducing the friction.
3. Polishing
Polishing reduces the unevenness of a surface. This will reduce interlocking between the surfaces.
4. Streamlining
Streamlining is the process where you make a machine in a shape that avoids air and water resistance. This reduces friction because a streamlined object cuts through the water and air molecules.
