Answer:
Plain carbon steel has no or trace external elements while alloy steel has high amount of other elements.
Explanation:
Plain carbon steel has no or trace amount of other elements while alloy steel has high amount of other elements in their composition.
The presence of other elements in alloy steel improvise several physical properties of the steel while plain carbon steel has the basic properties.
Answer:
Technician A
Explanation:
Galvanic corrosion is not on only one metal alone but caused when two metals are interacting. Thus, Duplicating the original installation method is a better option because re-using a coated bolt doesn't prevent galvanic corrosion because both materials must be coated and not just the bolt and in technician B's case he is coating just the bolt. Thus, technician B's method will not achieve prevention of galvanic corrosion but technician A's method will achieve it.
Answer:

Explanation:
The power needed to make the escalator working is obtained by means of the Work-Energy Theorem:




The mechanical efficiency of the escalator is:

