1.      Derive the equations describing the Mohr circle and make a drawing of the Mohr circle, containing the shear and the normal stresses, the failure envelope  and the angle of internal friction.

2.      Derive the settling velocity of sphere's and explain how in practice the settling velocity of grains has to be determined (consider laminar and turbulent settling and a transition zone).

3.      Derive the failure angles for passive and active soil failure. What is the ratio between the active and passive forces for an angle of internal friction of 45°.