Smooth surface hasa) less frictional forceb) more frictional forcec) s...
**Explanation:**
**Friction** is the force that opposes the relative motion between two surfaces in contact. It acts tangentially to the surface and has two types: static friction and kinetic friction.
**Static friction** is the force that prevents a stationary object from moving when a force is applied to it. It is directly proportional to the force applied and can vary in magnitude. The maximum static friction force that can be exerted is given by the equation:
**fs ≤ µsN**
where fs is the static friction force, µs is the coefficient of static friction, and N is the normal force exerted on the object.
**Kinetic friction** is the force that opposes the sliding motion between two surfaces in contact. It is generally smaller than the maximum static friction force and is given by the equation:
**fk = µkN**
where fk is the kinetic friction force, µk is the coefficient of kinetic friction, and N is the normal force exerted on the object.
**Smooth surfaces** have a low coefficient of friction, meaning they have less resistance to motion and therefore experience less frictional force compared to rough surfaces.
Now, let's consider the options given:
**a) Less frictional force:** Smooth surfaces have less frictional force because their coefficients of friction (both static and kinetic) are low. This means that it is easier for objects to slide or move on smooth surfaces with less resistance.
**b) More frictional force:** This option is incorrect because, as mentioned above, smooth surfaces have less frictional force due to their low coefficients of friction.
**c) Sometimes less and sometimes more force:** This option is incorrect because smooth surfaces consistently have less frictional force compared to rough surfaces.
**d) All of the above:** This option is incorrect as well because only option 'a' is correct.
Therefore, the correct answer is option 'A', smooth surfaces have less frictional force.
Smooth surface hasa) less frictional forceb) more frictional forcec) s...
The two sliding objects find less time to get interlocked against each other (objects and irregularities of surface). So they get less friction. Therefore sliding friction is always less than static friction.