The volume of water contained in reservoirs is generally measured in units of acre-ft. An acre-ft is a volume that covers an area of one acre to a depth of one foot (or an area of 2 acres with a depth of 0.5 ft). A Tan is a traditional Japanese unit of mass. Find the mass of water, in Tans, for Snohomish County's Martha Lake given the following: Volume of Lake

Explanation:

Given that,

The surface area is

A = 2acres.

Depth of the reservoir

d = 0.5ft

Volume = surface area × height.

Volume = 2 acres × 0.5ft

Volume = 1 acres-ft

1 acre = 43560 ft²

Then,

Volume = 1 × 43560ft²×ft

Volume = 43,560 ft³

Density of water is

ρ = 1000 kg/m³

1ft = 0.305m

1ft³ = 0.02837m³

ρ = 1000kg/m³ × 0.02837m³/ft³

ρ = 28.373 kg /ft³

Then, the mass of the reservoir can be calculated using

ρ = mass / volume

28.373 × volume = mass

Mass = 28.373 × 43560

Mass = 1,235,911.544 kg.

Then, 1 Tan = 60kg

Then,

Mass = 1,235,911.544 × 1Tan/60

Mass = 20,598.53 Tan