Frictional force is the force that opposes the motion of an object when it comes into contact with another surface. It acts in the opposite direction of the motion and can be caused by factors such as roughness or stickiness of the surfaces.
The formula for calculating frictional force is F = μN, where F is the frictional force, μ is the coefficient of friction, and N is the normal force exerted on the object by the surface it is in contact with.
The unit of frictional force is Newtons (N) in the SI system of measurement. In the Imperial system, it is measured in pounds (lbs).
Frictional force acts in the opposite direction of motion, so it can decrease the speed of an object. The amount of frictional force depends on the coefficient of friction and the normal force, and can vary depending on the surfaces in contact.
No, frictional force cannot be completely eliminated. However, it can be reduced by using lubricants or smoother surfaces, or by minimizing the normal force exerted on the object. In certain cases, such as in a vacuum, there is no frictional force present.