How far is it from the lighthouse to the ship horizontally if the lighthouse is 20 ft tall and shines a beam to the ship 25 ft long?

Also, which statement is correct?

(1 point)
Responses

x = approximately 24.5 yards; from the top of the lighthouse to the boat must be the shortest distance
x = approximately 24.5 yards; from the top of the lighthouse to the boat must be the shortest distance

x = 225 feet; the distance from the lighthouse to the ship must be the longest distance
x = 225 feet; the distance from the lighthouse to the ship must be the longest distance

x = 15 ft; the distance from the lighthouse to the ship must be the shortest distance
x = 15 ft; the distance from the lighthouse to the ship must be the shortest distance

x = 15 ft; the distance from the top of the lighthouse to the ship must be the longest distance

1 answer

To solve the problem, we can use the Pythagorean theorem. The situation can be visualized as a right triangle where:

  • The height of the lighthouse (20 ft) acts as one leg.
  • The beam of light to the ship (25 ft) acts as the hypotenuse.
  • We need to find the horizontal distance (x) from the lighthouse to the ship, which acts as the other leg of the triangle.

According to the Pythagorean theorem:

\[ a^2 + b^2 = c^2 \]

where:

  • \(a\) = horizontal distance (x)
  • \(b\) = height of the lighthouse (20 ft)
  • \(c\) = length of the beam (25 ft)

Now we can set up the equation:

\[ x^2 + 20^2 = 25^2 \]

Calculating the squares:

\[ x^2 + 400 = 625 \]

Now, subtract 400 from both sides:

\[ x^2 = 625 - 400 \] \[ x^2 = 225 \]

Now take the square root of both sides:

\[ x = \sqrt{225} = 15 \text{ ft} \]

So the horizontal distance from the lighthouse to the ship is 15 ft.

Now, to evaluate the statements:

  1. x = approximately 24.5 yards; from the top of the lighthouse to the boat must be the shortest distance - Incorrect.
  2. x = 225 feet; the distance from the lighthouse to the ship must be the longest distance - Incorrect.
  3. x = 15 ft; the distance from the lighthouse to the ship must be the shortest distance - Correct; this represents the shortest horizontal distance.
  4. x = 15 ft; the distance from the top of the lighthouse to the ship must be the longest distance - Incorrect; the hypotenuse (25 ft) is the longest distance.

Thus, the correct statement is:

x = 15 ft; the distance from the lighthouse to the ship must be the shortest distance.