15. In the solution of elasticity problem of a normal point load applied to the surface of a half plane that was solved by Boussinesq in 1878, the stresses and are given by:

and where is Poisson’s ratio. For lb and

, plot the stress components (each in a separate figure) as a function of r and z in the domain and in. Plot the coordinates r and z in the horizontal plane and the stresses in the vertical direction.