A block with mass 6 kg is placed on a rough surface with the coefficient of friction between the block and the surface equal to 0.6. In most cases, the coefficient of static and dynamic friction is different with the latter being smaller than the former. As only one value is given here both are taken to be the same.

The resistive force of friction that has to be overcome to move the object is equal to F = mu*N where mu is the coefficient of friction and N is the normal force. Here, mu = 0.6 and N = 6*9.8 = 58.8 N

F = 0.6*58.8 = 35.28 N

The work done in moving the block by a distance 12 m is equal to W = F*d = 35.28*12 = 423.36 J

The work done to move the block 12 m is 423.36 J