## 6 comments on “Solution to HW 2”

The confusion I have with this whoie continuum mechanics is the way we use operators especially the (multiplication sign). At a time its used as a scaler multiplication when am thinking of cross product at another time it is actually used as a cross product . It makes the whole thing difficult because am reading with the mind that am reading vecctors. I hope you can help me get out of this problem sir. I need clarification

2. oafak says:

OK, for simplicity, let us keep within the recommended text (Gurtin). If you go sufficiently wide you will get confused and that will not be your fault because each author sometimes takes the law into his or her hands and creates new rules for representation as he/she defines them.
The key to not get confused here is to know the character of the values you are dealing with: Between two vectors, a simple multiplication is the cross product. There is NO other meaning. When there is a circle surrounding the “multiplication” sign, you are dealing with a dyad creating tensor product. Between a tensor and a vector, there should be no symbol whatsoever. Some authors use a dot also to represent the operation of a tensor on a vector; but our main text is the more consistent rule. A dot between two vectors is the scalar product which creates a scalar out of the two vectors as you have been used to from your secondary school.

Okay sir,thank you sir