Final answer:
The velocity of air in the air duct can be calculated using the volume flow rate and the duct area. The velocity is 0.111 m/s.
Step-by-step explanation:
The velocity of air in the air duct can be calculated using the volume flow rate and the duct area. The volume flow rate is given as 340 cubic feet per minute (cfm). To convert this to cubic meters per second (m³/s), divide by 35.315. The area of the duct is given as 4.5 square feet. To convert this to square meters, multiply by 0.0929. Finally, divide the volume flow rate by the duct area to find the velocity.
Velocity = Volume flow rate / Duct area
Velocity = (340 / 35.315) / (4.5 * 0.0929)
Velocity = 0.111 m/s.