Design and conduct experiments to test few ways how friction may be reduced.

Friction helps us to do various works but it is also evil , and to reduce this evil there are many ways that are:-

a) Make the surfaces smoother by decreasing the roughness.

b) Lubricating the surfaces.

c) Make use of wheels that is use rolling friction rather than sliding friction.

d) Reduce the contact and hence increase the space between the surfaces.

e) Objects moving in fluids (liquids and gases) have streamline shapes to reduce friction by fluids called drag.

f) In cars not only due to tyres we can reduce friction but due to the design of the car that is the streamlined car and the aerodynamics technology can reduce the air drag or the friction due to air(wind).

EXPERIMENT-1, Smoother surfaces have less friction.

Place a smooth inclined plane on a smooth table. Put a mark with a pen at any point A on the inclined plane. Now let a dry cell move down from this point. How far will it move , note the distance from the end of the inclined plane. Now place a cloth or sandpaper on the table , provided , they do not have any wrinkles on them. Now repeat the above steps i.e. make the dry cell move from the same point A and when it stops note the distance from the foot of the inclined plane till where it stops. You will observe that the cell moved larger distance in the case of smooth table surface and moved less distance in the cloth case and the least distance in the sand paper case because of friction. So we need smoother surfaces to reduce friction.

EXPERIMENT-2, Rolling has less friction than sliding.

Take a few pencils which are cylindrical(not hexagonal or triangular) in shape. Place them parallel to each other on a smooth table. Place a thick book over them and try to push the book , you will observe that the pencils roll when we push the book accordingly. Now try to push the book when it is kept on table directly , you will feel more effort is applied in this case than the pencil rolling one. So we need to use wheels to reduce friction.