$(8$ pts$.)$ A ${10}^{\text{'}}{12}^{\text{'}}$ office with a ${10}^{\text{'}}$ ceiling requires three air changes per hour. Find the required CFM$.$

$(8$ pts$.)$ A rectangular $4"8"$ duct delivers air with a velocity of $12$ fps for $30$ minutes. Find the volume of air delivered to the room.

$(5$ pts$.)$ Find the pressure drop across a $50\text{'}$ length of $1"$ diameter Type L copper pipe. The initial pressure of the water is $30$ psi $.$

$(5$ pts$.)$ Find the voltage drop of a $120$ V single phase circuit that uses #$12$ AWG copper to carry $20$ amps for a distance of $75$ ft $.$

$(10$ pts$.)$ Find the size of copper conductor $($wire$)$ needed to be used on a $3-$phase, $208$ V circuit that supplies $12$ amps to a $3-$phase motor located $150\text{'}$ away from the electrical panel. The $V_d$ cannot exceed $3\%$ of the initial $208$ volts.

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