Real-Life Math -- Solution
Before you begin designing an irrigation system, you want to be
satisfied that the soil texture of the farm is suitable for irrigation. You
go to the farm and dig up a 150-pound soil sample. You sift through the soil
and find that it is made up of:
67.5 pounds sand
52.5
pounds silt
30 pounds clay
Question One:
Figure
out the percentages of each soil type:
67.5 pounds
= amount of sand
150 pounds = total amount of soil
67.5 / 150 x 100
= 45 percent
The soil is 45 percent sand.
52.5
pounds = amount of silt
150 pounds = total amount of soil
52.5 / 150
x 100 = 35 percent
The soil is 35 percent silt.
30
pounds = amount of clay
150 pounds = total amount of soil
30 / 150
= 20 percent
The soil is 20 percent clay.
Question
B:
If the soil contains 35 percent or more of sand
and silt, it is worth irrigating. The Racines' soil contains 45 percent
sand and 35 percent silt, and so it's suitable for irrigation.
"Mathematics
is the foundation for all engineers, including agricultural engineers," says
Loren Bode, an agricultural engineer. "We use it to calculate loads, stress,
strain, flow, mass balance and much more."