Can a vector have nonzero magnitude if a component is zero

Subject : Physics

Question:

1. Can a vector have nonzero magnitude if a component is zero? If no, why not? If yes, give an example.

2. Can a vector have zero magnitude and a nonzero component? if no, why not? If yes, give an example.

Expert Verified Solution:

Let’s break down each part of your question:

a. Can a vector have nonzero magnitude if a component is zero? If no, why not? If yes, give an example.

Yes, a vector can have nonzero magnitude even if one of its components is zero.

Explanation:

  • A vector is defined by its magnitude and direction, which are determined by its components along the coordinate axes.
  • The magnitude of a vector is calculated using the components in each direction, but the presence of a zero component does not necessarily mean the entire vector’s magnitude is zero. It simply means that the vector has no contribution in that particular direction.

Example: Consider a vector v\mathbf{v} in 2-dimensional space given by v=⟨4,0⟩\mathbf{v} = \langle 4, 0 \rangle.

  • Here, the vector has a nonzero component in the x-direction (4) and a zero component in the y-direction (0).
  • The magnitude of this vector is calculated as: Magnitude=(4)2+(0)2=16=4\text{Magnitude} = \sqrt{(4)^2 + (0)^2} = \sqrt{16} = 4
  • Thus, the vector ⟨4,0⟩\langle 4, 0 \rangle has a nonzero magnitude (4) even though one of its components (y) is zero.

b. Can a vector have zero magnitude and a nonzero component? If no, why not? If yes, give an example.

No, a vector cannot have zero magnitude if it has a nonzero component.

Explanation:

  • The magnitude of a vector is determined by all its components. If any component of the vector is nonzero, the magnitude will also be nonzero.
  • The magnitude of a vector v=⟨vx,vy⟩\mathbf{v} = \langle v_x, v_y \rangle is given by: Magnitude=vx2+vy2\text{Magnitude} = \sqrt{v_x^2 + v_y^2}
  • If either vxv_x or vyv_y is nonzero, then vx2+vy2v_x^2 + v_y^2 is greater than zero, which means the magnitude of the vector is also greater than zero.

Example: Consider a vector v=⟨0,3⟩\mathbf{v} = \langle 0, 3 \rangle.

  • This vector has a nonzero component (3 in the y-direction) and zero in the x-direction.
  • The magnitude of this vector is: Magnitude=(0)2+(3)2=9=3\text{Magnitude} = \sqrt{(0)^2 + (3)^2} = \sqrt{9} = 3
  • The vector ⟨0,3⟩\langle 0, 3 \rangle has a nonzero magnitude (3) despite having a zero component in the x-direction.

At last:

  • A vector can have a nonzero magnitude with a zero component.
  • A vector cannot have zero magnitude if it has any nonzero components.
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