In magnetic tape recording, the tape is subjected to tension while it is guided along its path. Tension in the tape causes elastic deformation that results in slight changes in length of the domains on which information is stored. Say the tape has an average modulus of 8Gpa , a thickness of 8 micro meters , and a width of 14 mm . Let the unit of stored information occupy a length 0.6 micro meters in a tape that has no tension.