Math Problem Statement

Diketahui vektor \(\vec{p} = 5\hat{i} - 3\hat{j} + 2\hat{k}\) dan \(\vec{q} = 2\hat{i} + 4\hat{j} + 2\hat{k}\), proyeksi vektor \(\vec{p}\) pada vektor \(\vec{q}\) adalah ...

Solution

To solve the problem of finding the projection of vector p\vec{p} on vector q\vec{q}, let's break it down step-by-step.

We are given: p=5i^3j^+2k^\vec{p} = 5\hat{i} - 3\hat{j} + 2\hat{k} q=2i^+4j^+2k^\vec{q} = 2\hat{i} + 4\hat{j} + 2\hat{k}

Formula for the projection of p\vec{p} on q\vec{q}:

Projection of p on q=pqq2q\text{Projection of } \vec{p} \text{ on } \vec{q} = \frac{\vec{p} \cdot \vec{q}}{\|\vec{q}\|^2} \vec{q}

Step 1: Dot product pq\vec{p} \cdot \vec{q}

pq=(5)(2)+(3)(4)+(2)(2)=1012+4=2\vec{p} \cdot \vec{q} = (5)(2) + (-3)(4) + (2)(2) = 10 - 12 + 4 = 2

Step 2: Magnitude squared of q\vec{q} (q2\|\vec{q}\|^2)

q2=(2)2+(4)2+(2)2=4+16+4=24\|\vec{q}\|^2 = (2)^2 + (4)^2 + (2)^2 = 4 + 16 + 4 = 24

Step 3: Projection calculation

Projection of p on q=224q=112q\text{Projection of } \vec{p} \text{ on } \vec{q} = \frac{2}{24} \vec{q} = \frac{1}{12} \vec{q}

Step 4: Substitute q\vec{q}

112q=112(2i^+4j^+2k^)=212i^+412j^+212k^\frac{1}{12} \vec{q} = \frac{1}{12}(2\hat{i} + 4\hat{j} + 2\hat{k}) = \frac{2}{12}\hat{i} + \frac{4}{12}\hat{j} + \frac{2}{12}\hat{k} =16i^+13j^+16k^= \frac{1}{6}\hat{i} + \frac{1}{3}\hat{j} + \frac{1}{6}\hat{k}

Final Answer:

Projection of p on q=16i^+13j^+16k^\text{Projection of } \vec{p} \text{ on } \vec{q} = \frac{1}{6}\hat{i} + \frac{1}{3}\hat{j} + \frac{1}{6}\hat{k}

Would you like further clarification or assistance with this solution?

Related Questions:

  1. What is the angle between vectors p\vec{p} and q\vec{q}?
  2. How do you calculate the unit vector of q\vec{q}?
  3. What is the orthogonal projection of p\vec{p} onto a plane normal to q\vec{q}?
  4. How can you generalize the projection formula for n-dimensional vectors?
  5. What is the physical interpretation of projecting one vector onto another?

Tip:

Always verify calculations for the dot product and magnitude carefully to avoid minor errors in vector operations!

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Math Problem Analysis

Mathematical Concepts

Vector Algebra
Dot Product
Projection of Vectors

Formulas

Projection of \(\vec{p}\) on \(\vec{q}\): \( \frac{\vec{p} \cdot \vec{q}}{\|\vec{q}\|^2} \vec{q} \)
Dot Product: \( \vec{p} \cdot \vec{q} = p_xq_x + p_yq_y + p_zq_z \)
Magnitude of a Vector: \( \|\vec{q}\| = \sqrt{q_x^2 + q_y^2 + q_z^2} \)

Theorems

Properties of Dot Product

Suitable Grade Level

Grades 11-12