Question

A percolation tube is used to determine the percolation rate of a soil sample in mL/cm²/minute. To conduct the test, a certain volume of water is poured through the soil sample, and the time it takes for the water to pass through the sample is measured. Calculate the percolation rate using the following data.

b. A percolation tube has a radius of 4.5 cm; 50 mm of water is poured onto the surface of the soil, and it takes 10 seconds for the water to disappear from the surface of the soil.
A) 2.36 mL/cm²/minute
B) 4.71 mL/cm²/minute
C) 9.42 mL/cm²/minute
D) 18.84 mL/cm²/minute

Answer 1

To calculate the percolation rate, we use the formula: Percolation rate = (Volume of water)/(Surface area of soil sample * Time). We can calculate the surface area of the soil sample using the given radius of the percolation tube. By plugging in the values, we find that the percolation rate is approximately 0.0079 cm/min. The correct percolation rate is 4.71 mL/cm²/minute.

Step-by-step explanation:

To calculate the percolation rate, we need to use the formula:

Percolation rate = (Volume of water)/(Surface area of soil sample * Time)

First, we need to calculate the surface area of the soil sample, which is given by the formula: Surface area = π *
`r^2`, where r is the radius of the percolation tube.

In this case, the radius of the percolation tube is 4.5 cm, so the surface area of the soil sample is: Surface area = π *
`(4.5)^2` = 63.62
`cm^2`.

Next, we can calculate the percolation rate using the given data. The volume of water poured onto the soil sample is 50 mm, which is equal to 5 cm. The time it takes for the water to disappear is 10 seconds.

Plugging these values into the formula, we get:

Percolation rate = (5 cm) / (63.62
`cm^2` * 10 seconds)

Simplifying, we find that the percolation rate is approximately 0.0079 cm/min.

So, the correct answer is B) 4.71 mL/cm²/minute.

Answer 2

To calculate the percolation rate, find the volume of water passed through the soil sample and the time it took. The percolation rate is the volume of water per unit area per unit time. The percolation rate is 0.500 mL/cm²/minute.

Step-by-step explanation:

To calculate the percolation rate, we need to find the volume of water that passed through the soil sample and the time it took. The percolation rate is defined as the volume of water per unit area per unit time.

First, we need to convert the radius of the percolation tube from cm to mm. The radius is 4.5 cm, which is equal to 45 mm.

The area of the tube is calculated using the formula A = πr², where r is the radius. So, the area of the tube is A = π(45)² = 6349.62 mm².

Now, let's calculate the volume of water that passed through the soil sample. The height of water poured is given as 50 mm. The volume of water is calculated using the formula V = Ah, where A is the area of the tube and h is the height of water. So, the volume of water is V = 6349.62 mm² * 50 mm = 317,481 mm³.

Next, we need to convert the volume of water from mm³ to cm³. Since 1 cm³ = 1000 mm³, the volume of water is 317,481 mm³ / 1000 = 317.481 cm³.

Finally, we need to find the percolation rate in mL/cm²/minute. The time it took for the water to disappear from the surface of the soil is given as 10 seconds. So, the percolation rate is calculated using the formula percolation rate = volume / area / time. Substituting the values, we get percolation rate = 317.481 cm³ / 6349.62 mm² / 10 seconds = 0.500 mL/cm²/minute.

Therefore, the percolation rate is 0.500 mL/cm²/minute, which is closest to option A) 2.36 mL/cm²/minute.