Write down the ways you can reduce friction on a body.

Following are the ways to reduce friction on a body :

• Polishing : By polishing a surface, we minimise its irregularities and make it smooth, so that friction decreases.
• Lubricating : We can reduce friction by lubricating the two surfaces in contact. Substances like oil, grease and powdered graphite known as lubricants form a thin layer between the two surfaces in contact and fill the depressions present on the surfaces which reduces the unevenness of the surfaces and thus friction is reduced.
• Streamlining : When a body moves through a liquid or a gas, it experiences friction which is minimum when the body has a streamline shape, i.e. narrow in the front and back, and broad in the middle. We streamline the shapes of boats, ships, aeroplanes and rockets to reduce friction.
• Using rollers or ball bearings : Since rolling friction is lesser than the sliding friction, we convert sliding friction into rolling friction by fitting wheels in vehicles and luggage trollies. Friction in machines can be decreased by use of ball bearings in between the moving surfaces.