Vector →A which is directed along an x axis, is to be added to the vector →B which has a magnitude of 2.5m. The sum is third vector directing along the y axis with a magnitude that is 4.10times that of a vector →A What is the magnitude of →A?

Respuesta :

Answer:

0.592 m

Explanation:

Let i and j be the unit vector in the direction of x and y respectively. And let [tex]x_A[/tex] be the x component of vector A. Therefore:

[tex]\vec{A} = x_A\hat{i}[/tex]

Since the resulting vector only directs along the y axis, the x component of vector B must have canceled the x component of vector A. Let [tex]y_B[/tex] be the y component of vector B. We have

[tex]\vec{B} = -x_A\hat{i} + y_B\hat{j}[/tex]

So [tex]\vec{A} + \vec{B} = y_B\hat{j}[/tex]

This resulting vector has a magnitude 4.1 times vector A's, or [tex]4.1x_A[/tex]

[tex]y_B = 4.1x_A[/tex]

Substitute this into vector B equation we have

[tex]\vec{B} = -x_A\hat{i} + 4.1x_A\hat{j}[/tex]

Since the magnitude of vector B is 2.5

[tex]|\vec{B}| = \sqrt{x_A^2 + (4.1x_A)^2} = 2.5[/tex]

[tex]17.81x_A^2 = 2.5^2 = 6.25[/tex]

[tex]x_A^2 = 6.25 / 17.81 = 0.35[/tex]

[tex]x_A = \sqrt{0.35} = 0.592m[/tex]

So the magnitude of vector A is 0.592 m