It is usually seen that during rainy days we tend to slip because rainwater acts as a lubricant between our feet and ground. This lubrication (rainwater) converts dry friction into fluid friction. That is, the friction between feet and ground reduces, making us slip. Therefore, due to less friction, we slip on a rainy day.
What is friction?
The resistance offered by the surfaces that are in contact with each other when they move over each other. Friction is dependent on the smoothness or roughness of the two surfaces that are in contact with each other. When the surface is smooth, the friction between the two reduces as there is no much interlocking of irregularities. At the same time, the surface is rough, friction increases.
- The motion of pistons in a cylinder is an application of friction.