Math Problem Statement

Find the component form of the sum of \( \mathbf{u} \) and \( \mathbf{v} \) with direction angles \( \theta_u \) and \( \theta_v \), given the magnitudes and angles: \( |\mathbf{u}| = 14 \), \( \theta_u = 45^\circ \), \( |\mathbf{v}| = 30 \), \( \theta_v = 180^\circ \).

Solution

To find the component form of the sum of vectors u\mathbf{u} and v\mathbf{v} with the given magnitudes and angles:

Step 1: Write the components of each vector

For a vector in component form given magnitude u|\mathbf{u}| and direction angle θ\theta, the components are: u=ucosθu,usinθu\mathbf{u} = \langle |\mathbf{u}| \cos \theta_u, |\mathbf{u}| \sin \theta_u \rangle v=vcosθv,vsinθv\mathbf{v} = \langle |\mathbf{v}| \cos \theta_v, |\mathbf{v}| \sin \theta_v \rangle

Substituting the given values:

  • Magnitude of u\mathbf{u}: u=14|\mathbf{u}| = 14, θu=45\theta_u = 45^\circ
  • Magnitude of v\mathbf{v}: v=30|\mathbf{v}| = 30, θv=180\theta_v = 180^\circ

Step 2: Compute the components

For u\mathbf{u}: u=14cos45,14sin45\mathbf{u} = \langle 14 \cos 45^\circ, 14 \sin 45^\circ \rangle Using cos45=sin45=22\cos 45^\circ = \sin 45^\circ = \frac{\sqrt{2}}{2}: u=1422,1422=72,72\mathbf{u} = \langle 14 \cdot \frac{\sqrt{2}}{2}, 14 \cdot \frac{\sqrt{2}}{2} \rangle = \langle 7\sqrt{2}, 7\sqrt{2} \rangle

For v\mathbf{v}: v=30cos180,30sin180\mathbf{v} = \langle 30 \cos 180^\circ, 30 \sin 180^\circ \rangle Using cos180=1\cos 180^\circ = -1 and sin180=0\sin 180^\circ = 0: v=30(1),300=30,0\mathbf{v} = \langle 30 \cdot (-1), 30 \cdot 0 \rangle = \langle -30, 0 \rangle

Step 3: Add the components of u\mathbf{u} and v\mathbf{v}

u+v=72+(30),72+0\mathbf{u} + \mathbf{v} = \langle 7\sqrt{2} + (-30), 7\sqrt{2} + 0 \rangle Simplify: u+v=7230,72\mathbf{u} + \mathbf{v} = \langle 7\sqrt{2} - 30, 7\sqrt{2} \rangle

Final Answer:

The component form of u+v\mathbf{u} + \mathbf{v} is: u+v=7230,72\mathbf{u} + \mathbf{v} = \langle 7\sqrt{2} - 30, 7\sqrt{2} \rangle

Let me know if you want further clarification or numerical approximations! Here are five related questions to deepen your understanding:

  1. How do we determine the magnitude of the resulting vector u+v\mathbf{u} + \mathbf{v}?
  2. What are the steps to calculate the direction angle of u+v\mathbf{u} + \mathbf{v}?
  3. How would the solution change if θv\theta_v were a different angle, such as 9090^\circ?
  4. What role does trigonometric identity play in vector decomposition?
  5. Can you derive the component form for three vectors instead of two?

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Math Problem Analysis

Mathematical Concepts

Vector Addition
Trigonometry
Component Form of Vectors

Formulas

\( \mathbf{u} = \langle |\mathbf{u}| \cos \theta_u, |\mathbf{u}| \sin \theta_u \rangle \)
\( \mathbf{v} = \langle |\mathbf{v}| \cos \theta_v, |\mathbf{v}| \sin \theta_v \rangle \)
Sum of vectors: \( \mathbf{u} + \mathbf{v} = \langle u_x + v_x, u_y + v_y \rangle \)

Theorems

Vector Decomposition

Suitable Grade Level

Grades 9-12