I have 2 questions please help if you can

1) Shielding gasses are used with a pressure regulator. The regulator screw should be before the cylinders valve(s) are opened

2) Do not not touch any electrode holder or GTAW torch with bare skin or wet gloves. A fatal shock may result

A. new

B. large diameter

C. uninsulated

D. insulated

E. old-fashioned

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?

Water vapor initially at 10 bar and 400 °c is contained within a piston-cylinder assembly. the water lost heat to the surrounding according to isochoric (iso-volumetric) process until its temperature is 150 °c. the water is then condensed isothermally to saturated liquid. for the water as a system, calculate the work in kj/kg