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A construction worker needs to determine the volume of a sandpile in a construction yard, as shown. A line along the surface of the sandpile from the ground to the top of the sandpile makes a 40° angle with the ground at point R. The length of the slant side of the sandpile, RT, from the ground to the top of the sandpile is 20 meters. What is the volume of the sandpile, to the nearest cubic meter?

User Jeff Carey
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1 Answer

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Final answer:

To find the volume of a sandpile which is shaped like a cone, we use the slant height and the angle with the ground to calculate the radius and height, and then apply the formula for the volume of a cone.

Step-by-step explanation:

To calculate the volume of the sandpile, we need to determine the shape of the sandpile first. Given the description, it is logical to assume the sandpile has a conical shape. Now, to calculate the volume of a cone, we use the formula:

V = ⅓ π r^2 h

Where V is the volume, r is the radius of the base, h is the height, and π is Pi (approximately 3.14159). Given the slant height (RT) and the angle (40°), we can calculate the radius (r) and the height (h) of the sandpile using trigonometric relations.

Let's calculate the radius (r) and height (h) using the following trigonometric functions:

  • Sin(40°) = h / 20m
  • Cos(40°) = r / 20m

By solving these equations, we find:

  • h = 20m * Sin(40°)
  • r = 20m * Cos(40°)

Once we have the values for r and h, we substitute them back into the volume formula to find the volume of the sandpile.

The calculations are as follows:

  • h = 20m * 0.6428 (approximate value of Sin(40°))
  • r = 20m * 0.7660 (approximate value of Cos(40°))
  • V = ⅓ π (20m * 0.7660)^2 * (20m * 0.6428)

After performing the calculation, we round the volume to the nearest cubic meter to get the final answer.

User Andrew Vit
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