If the surface is rough then the average force needed to move the wooden block will be more as the friction between the surfaces will be more.
Hence, the least force will be required on the smoothest surface and the greatest force will be required for the roughest surface.
a) Hence, the order will be: B > D > A > C
b) When the surface is glued then the force of friction will increase. Hence, it will require more force to move the wooden block on the surface. Hence, the more required will be more than 105 N.
