Question

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, 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

Answer 1

Here we have to compare and see where on what surfaces the force of friction will be more and on what surfaces it will be less. The speed of a real-life car also depends on friction.

Complete step by step answer:
We all know that frictional force is a resisting force. When the surface of one object comes into contact with the surface of another, friction is the force that resists motion. A machine’s mechanical advantage is reduced by friction, or we can say due to friction the ratio of output to input is reduced. Friction in the tyres helps vehicles to remain on the ground and friction in the clutch helps it to drive. The force of friction refers to the force created by two surfaces that touch and slip against each other. Frictional forces are primarily influenced by the texture of the surface and the amount of force that brings them together. So, we can say the more rough a surface is, the more is the force of friction. A slippery or smooth surface has less friction. A wet marble floor is the smoothest surface followed by dry marble floor, then newspaper and at last towel. The towel has the roughest surface. The force of friction acting on the car on different surfaces in increasing order will be: Wet marble floor, dry marble floor, newspaper, and towel.
Hence, option A is correct.

Note: It may be a bit confusing as to whether a dry marble floor or a wet marble floor will be smoother, but a frictional force on a slippery surface is even less than a smooth surface. Since, the wet marble floor will be slippery than a dry one, so friction is less on the wet floor.