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What are the magnitude and direction of a vector that has an x component of -38.0 units and a y component of -60.0 units?

User Fixus
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1 Answer

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Final answer:

The magnitude of the vector with x and y components of -38.0 and -60.0 units respectively is 70.71 units, and its direction is approximately 237.5°, taking into account that it lies in the third quadrant.

Step-by-step explanation:

The magnitude and direction of a vector can be found by using its x and y components. In this case, the given vector has components -38.0 units in the x direction and -60.0 units in the y direction.

First, to find the magnitude of the vector, we can use the Pythagorean theorem:

  1. Calculate the square of each component: (-38.0)^2 and (-60.0)^2.
  2. Add these squared values: 1444 + 3600.
  3. Take the square root of the sum: √(1444 + 3600) = 70.71 units.

Therefore, the magnitude of the vector is 70.71 units.

To determine the direction of the vector, we find the angle it makes with the positive x-axis using the tangent function and arctan (also known as tan^{-1} or atan):

  1. Calculate the ratio of y to x: (-60.0) / (-38.0).
  2. Take the arctan of this ratio: arctan(60.0 / 38.0).
  3. The angle is found to be approximately 57.5°.

However, because both components are negative, the vector lies in the third quadrant, where the reference angle given by arctan must be adjusted to find the angle from the positive x-axis. We do this by adding 180° to the reference angle (because angles in the third quadrant are between 180° and 270°).

Therefore, the angle is approximately 57.5° + 180° = 237.5°.

In summary, the vector has a magnitude of 70.71 units and a direction of approximately 237.5°.

User Peter Boone
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