Final answer:
The force required to drag an object along a horizontal plane is the frictional force. It is necessary to overcome this force to move the object, which depends on the object's weight and the coefficient of friction between contacting surfaces.
Step-by-step explanation:
The force required to drag an object along a horizontal plane is the frictional force. This force opposes the motion of two surfaces sliding past each other. In the context of the question, where an object with weight w is dragged along a horizontal surface, we need to consider factors like the force of gravity, the normal force, and the coefficient of friction between the object and the surface.
For an object resting on a horizontal surface, its weight w acts vertically downward and is given by w = mg, where m is the mass of the object and g is the acceleration due to gravity. The normal force is equal and opposite to the weight of the object. The frictional force is calculated by f = μN, where μ is the coefficient of friction and N is the normal force.
In conclusion, the force required to move the object is at least equal to the frictional force, which needs to be overcome to initiate and maintain the motion of the object along the horizontal surface.