A block of mass m slips on a rough horizontal table under the action of a horizontal force applied to it. The coefficient of friction between the block and the table is μ. The table does not move on the floor. Find the total frictional force applied by the floor on the legs of the table. Do you need the friction coefficient between the table and the floor or the mass of the table?
When the body is slipping from the surface, the maximum frictional force is acting on it. From the free body diagram (ii)
R = mg
F − μR = 0
⇒ F = μR = μmg
Since, table is at rest, the frictional force at the legs of the table will also be μR. Let the frictional force be f, then according to the diagram,
f − μR = 0
⇒ f = μR = μmg
Therefore, the total frictional force on the table by the floor is μmg