Question

Plowing effect as a cause for friction can be understood in which of the following cases?

• A. When two rough surfaces are in contact
• B. When one of the surfaces in contact is smooth and can undergo deformations in its shape
• C. When both the surfaces are smooth
• D. None of the above

Answer 1

The correct option is B

When one of the surfaces in contact is smooth and can undergo deformations in its shape

When an object slides on a smooth surface, there can be deformations in its shape and this causes friction. This is referred as the plowing effect. Take an example of a brick moving on a grass field to understand this better. The surface of grass is "smooth" in the sense that its shape can be deformed easily.