Alida runs her toy car on dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be (a) wet marble floor, dry marble floor, newspaper and towel. (b) newspaper, towel, dry marble floor, wet marble floor. (c) towel, newspaper, dry marble floor, wet marble floor. (d) wet marble floor, dry marble floor, towel, newspaper

The answer is (a) wet marble floor, dry marble floor, newspaper, and towel.

Explanation

The force of friction depends on the nature of the surface in contact. The rougher the surface, the more is the friction between the surfaces in contact and vice-versa. The friction between the surface of a toy car and towel is more than compared to newspaper because the surface of towel is rough. The surface of newspaper is rougher than the surface of dry marble floor; hence its friction is more than dry marble floor. The force of friction of wet marble floor is the least due to presence of a layer of water which makes the surface of marble smooth. Roughness present in the given surfaces can be arranged in ascending order as wet marble floor, dry marble floor, newspaper and towel.