Aring-shaped seal, made from a viscoelastic material, is used to seal a joint between two rigid pipes. when incorporated in the joint, the seal is held at a xed compressive strain of 0.2. assuming that the seal can be treated as a maxwell model, determine the time before the seal begins to leak under and internal uid pressure of 0.3 mpa. it can be assumed that the relaxation time 0 of the material is 300 days and the short-term (instantaneous) modulus of the material is 3 mpa.