A block of mass \(200\text{ kg}\) is pulled along rough horizontal ground at a constant speed of \(v\text{ m s}^{-1}\) by a horizontal rope attached to a winch. The coefficient of friction between the block and the ground is \(0.8\). The winch is working at a constant rate of \(4000\text{ W}\).

Find the value of \(v\). [4]