sol = With[{c = 1, k = 1/320, h = 0.08}, RecurrenceTable[{v[i, j] == c ((1 - (2 k)/h^2) v[i, j - 1] + ( k (v[i + 1, j - 1] + v[i - 1, j - 1]))/h^2), v[i, 0] == UnitStep[2. - i h] UnitStep[i h + 2] 100}, v, {i, -70, 70}, {j, 0, 300}]];
ListPlot3D[Transpose[sol], Mesh -> None, PlotStyle -> {Orange, Specularity[White, 10]}, ImageSize -> 300, AspectRatio -> 1]