16. A gear system has 36 teeth and 27 teeth and 18 and 12 respectively, what is the gear ratio between the 1st and 2nd gears and the 3rd and 4th gears?
A) .75 and .66
B).75 and 1.5
C) 1.33 and .66
D).75 and 3

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length

What is the major difference between thermoplastics and thermosetting plastics from the polymerization structure point of view?

A)-in the process of engineering design, explain the contribution of material selection. b)- explain the procedure of synthesis as is employed in engineering design. c)- is there any relationship between ergonomics and engineering design? explain. d)- safety consideration in engineering design includes human, product and the enviroment . explain how safety will be incorporated into the design?