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

AcademicPhysicsNCERTClass 8

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

Explanation:

We have to arrange the force of friction acting on the car on different surfaces in increasing order. Let us know first the factor that affects the friction offered by a surface-

Factor on which friction depends:

The friction offered by the surface of any object depends on the nature of the surface such as roughness etc. Friction between two surfaces increases as the roughness of the surfaces increases.

Increasing order of friction at different surfaces:

Here, wet marble is much smoother than dry marble, dry marble is smoother than newspaper, and towel and newspaper are smoother than a towel.

Therefore, the increasing order of friction is as below:

Wet marble floor < Dry marble floor < Newspaper < Towel

So, option $(a)$ is correct.

raja
Updated on 10-Oct-2022 13:24:48

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