What is the direction of the resultant vector if two vectors having eq...
If one is heading towards positive X-axis and the other is in the other direction opposite to the first one, with both having the same length and having an angle between them being obtuse, means that the direction is to be in the direction of either 1st quadrant or in the 4th quadrant.
View all questions of this test
What is the direction of the resultant vector if two vectors having eq...
Solution:
Given, two vectors have the same length. One vector is parallel to the positive x-axis and the other vector is making 165 degrees with it and heading in the opposite direction of the first one.
Let's draw the vectors to understand the given information.
From the above diagram, we can see that the angle between the two vectors is 165 - 180 = -15 degrees.
To find the direction of the resultant vector, we need to find the sum of two vectors.
Let Vector A be parallel to the x-axis and Vector B be making 165 degrees with it and heading in the opposite direction of that of the first one.
Vector A can be represented as (a, 0) and Vector B can be represented as (-b cos 15, -b sin 15).
The sum of two vectors is Vector A + Vector B = (a - b cos 15, -b sin 15)
From the above equation, we can see that the x-component of the resultant vector is a - b cos 15 which is positive if a > b cos 15 and negative if a < b="" cos="" />
Similarly, the y-component of the resultant vector is negative because the angle of Vector B is in the fourth quadrant.
Therefore, the direction of the resultant vector is either in the first quadrant or in the fourth quadrant.
Hence, the correct option is (c) It is either in the 1st quadrant or in the 4th quadrant.