Below is the PDF version of lecture 5 in powerpoint. There are also links to two supplemental videos on the topic of elasticity. The second is used on your 2nd homework assignment.
powerpoint lecture 5 PDF format
Youtube video lecture 5 if you phone does not have powerpoint
Youtube video supplementary lecture - https://www.youtube.com/watch?v=5UKw4blQdscYoutube video supplementary lecture - https://www.youtube.com/watch?v=nAT_shQGlIk