Particle $x$ has an aerodynamic diameter $(AED)=6\mathrm{.}0mm$ and a specific gravity $(SG)=1\mathrm{.}5.$ Particle $Y$ has an AED$=1\mathrm{.}5$ and a $SG=3\mathrm{.}5.$ Which will fall faster particle X or Y$?$ Show your work.

If a mineral has a quartz silica content of $25\%,$ what is the PEL for this mineral? Show your work.

What is the purpose of desiccating filters for gravimetric analysis?

The minimum level of detection for your analytical balance is $0\mathrm{.}01mg.$ For how many minutes do you need to run the pump to obtain a minimum detectable sample of respirable particulates not otherwise classifiable? Use $10\%$ of the TLV $(3m\frac{g}{m^3})$ and a flow rate of $1\mathrm{.}5lpm$ to complete your calculations.