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Industrial Hygiene and Toxicology Calculations 1. If the air in a 12-in diameter duct with an air flow of 1,500 ft3/min and a velocity of 14 ft/min flows into a 6-in diameter duct, what are the new flow rate and velocity? Show all work. (20 pts)

2. If an employee is exposed to continuous sound levels for 2 hours at 95 dB and is then exposed to sound levels below 65 dB for the rest of the 8 hour day, what is the employee's 8 hour TWA in dBA using OSHA's calculations? Does this employee exceed OSHA's PEL? Does this employee need to be in a hearing conservation program? Show all work. (20 pts)

3. Complete the following table with the appropriate molecular weights for each chemical and convert the following concentrations from parts per million (ppm) to milligrams per meter3 (mg/m3) or from mg/m3 to ppm. Show all work. (20 pts)