Question

Difficulty: EasyDirection and Distance Test

A municipal engineer begins inspecting a road pipeline from point AA by walking 12 m12\text{ m} towards the East. She then turns to her right and walks 5 m5\text{ m} to reach point BB. What is the shortest direct distance between point AA and point BB, and in which direction is point BB relative to point AA?

  1. 13 m13\text{ m}, South-EastAnswer
  2. B
    17 m17\text{ m}, South-East
  3. C
    13 m13\text{ m}, North-East
  4. D
    17 m17\text{ m}, North-West

Answer

The shortest direct distance between point AA and point BB is 13 m13\text{ m}, and point BB lies in the South-East direction relative to point AA.
The engineer moves 12 m12\text{ m} East and then turns right (South) to walk 5 m5\text{ m}. The straight-line distance forms the hypotenuse of a right triangle with perpendicular sides of 12 m12\text{ m} and 5 m5\text{ m}, calculated as 122+52=13 m\sqrt{12^2 + 5^2} = 13\text{ m}. Since point BB lies to the East and South of point AA, its position relative to point AA is South-East.

Step-by-Step Solution

1
Determine the direction of movement.
Initial movement is 12 m12\text{ m} East. Turning right while facing East leads to facing South, followed by walking 5 m5\text{ m} South.
A right turn relative to East points directly South.
2
Identify the relative cardinal direction of point BB from point AA.
Point BB is displaced Eastward and Southward from point AA, placing it in the South-East quadrant relative to point AA.
Combining an Eastward vector with a Southward vector results in a South-East displacement.
3
Calculate the direct straight-line distance using the Pythagorean theorem.
Distance=122+52=144+25=169=13 m\text{Distance} = \sqrt{12^2 + 5^2} = \sqrt{144 + 25} = \sqrt{169} = 13\text{ m}.
The perpendicular legs of 12 m12\text{ m} and 5 m5\text{ m} form a right-angled triangle where the hypotenuse represents the direct distance.

Key Concept

Direction reorientation and displacement calculation using the Pythagorean theorem
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