define friction.name two methods of reducing friction
Answers
Answer:
What is friction?
Friction is a contact force which acts opposite to the direction of motion. For example friction helps us to walk, when our tries to slip back, friction acts in opposite direction, i.e. forward direction and prevents us from slipping.
Methods of reducing friction:
☆ Using ball bearings in machine parts.
☆ Using lubricants in the parts of machine, this process is known as lubrication.
☆ Sprinkling of powder on carom board.
☆ Making the surface of the object smoother.
☆ By placing rollers under the object.
There are three types of friction:
☆ Static friction
☆ Sliding friction
☆ Rolling friction
Static friction > Sliding friction > Rolling friction
Answer:
Methods for Reducing Friction
☆ Moving parts of machines are covered with oil or grease, which make the effect of friction less.
☆ The surfaces are highly polished, to eliminate the irregularities thus making the surface smooth and reducing friction to a great extent.
☆ Fluid friction is reduced by using streamlined shapes in airplanes or ships.
☆ Use of wheels between surfaces moving over each other reduces friction as rolling friction is less than the sliding friction.
☆ Ball bearings are used in machines to reduce friction. These are tiny steel balls often placed between moving parts of machines which reduces friction and saves a lot of energy.