Final answer:
To provide 1 inch of water across the bed, you should let the water run for approximately 198.93 minutes.
Step-by-step explanation:
To find the number of minutes you should let the water run to provide 1 inch of water across the bed, you need to calculate the volume of water needed. First, convert the dimensions of the bed to feet. Since there are 12 inches in 1 foot, the bed is 8 feet wide, 60 feet long, and 4/12 = 1/3 feet deep. The volume of water needed is then given by: V = Width * Length * Depth. Plug in the values: V = 8 feet * 60 feet * 1/3 feet = 160 cubic feet.
Next, convert the volume from cubic feet to gallons. Since there are 7.48 gallons in 1 cubic foot, multiply the volume by 7.48: V = 160 cubic feet * 7.48 gallons/cubic foot = 1193.6 gallons.
Finally, divide the volume of water needed by the flow rate of the irrigation system to find the number of minutes: Minutes = Volume / Flow Rate. Plug in the values: Minutes = 1193.6 gallons / 6 gallons/minute ≈ 198.93 minutes. Therefore, you should let the water run for approximately 198.93 minutes to provide 1 inch of water across the bed.