4. Three conveyor belts are arranged to transport material and the conveyor belts must be started in reverse sequence (the last one first and the first one last) so that the material does not get piled on to a stopped or slow-moving conveyor. Each belt takes 45 seconds to reach full speed. Design a ladder logic that would control the start and stop of this three-conveyor system.

Plot schematically the tensile stress versus strain curves for a typical thermoplastic material at a temperature below its glass transition temperature (tg and at a temperature above its tg, respectively. do the same for a typical thermosetting material. list in a table any differences or similarities between the two materials at t> tg and t < tg, respectively, and relate them to the structures of the two types of polymers