Which of the following is a benefit of creating 3D assembly models prior to production. A. It can help to eliminate assembly errors before the product is built.

B. It creates less work on the part of the designer,

C. It identifies problems that can not be discovered it building the actual product

D. It eliminates the need for production paperwork

On solidification from a melt, the polymer polyethylene forms a semi-crystalline spherulite structure. (i) sketch an individual spherulite and label the amorphous and crystalline regions. (ii) draw a schematic to show the changes in specific volume with temperature during cooling from the melt, comparing it to the theoretical extremes of fully crystalline and fully amorphous (indicate tm and tg)