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Grade 12Mechanics

with the help of vector addition prove that vector addition is associated

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8 Years agoGrade 12
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ApprovedApproved Tutor Answer11 Months ago

To demonstrate that vector addition is associative, we need to show that when we add three vectors, the way we group them does not affect the final result. In mathematical terms, this means that for any vectors **A**, **B**, and **C**, the equation (**A** + **B**) + **C** = **A** + (**B** + **C**) must hold true. Let's break this down step by step.

Understanding Vector Addition

Vectors are quantities that have both magnitude and direction. When we add vectors, we can visualize this using the tip-to-tail method or by using components. The associative property states that the grouping of vectors does not change their sum.

Using Components for Clarity

Let’s express vectors **A**, **B**, and **C** in terms of their components:

  • **A** = (A₁, A₂)
  • **B** = (B₁, B₂)
  • **C** = (C₁, C₂)

Now, we can compute the left-hand side of our associative property:

Calculating the Left Side: (**A** + **B**) + **C**

First, we add **A** and **B**:

  • **A** + **B** = (A₁ + B₁, A₂ + B₂)

Next, we add this result to **C**:

  • (A₁ + B₁, A₂ + B₂) + (C₁, C₂) = (A₁ + B₁ + C₁, A₂ + B₂ + C₂)

Calculating the Right Side: **A** + (**B** + **C**)

Now, let’s add **B** and **C** first:

  • **B** + **C** = (B₁ + C₁, B₂ + C₂)

Then, we add this result to **A**:

  • (A₁, A₂) + (B₁ + C₁, B₂ + C₂) = (A₁ + (B₁ + C₁), A₂ + (B₂ + C₂))

Comparing the Results

Now we can compare the two results:

  • From the left side: (A₁ + B₁ + C₁, A₂ + B₂ + C₂)
  • From the right side: (A₁ + (B₁ + C₁), A₂ + (B₂ + C₂))

Both expressions simplify to the same final components:

  • X-component: A₁ + B₁ + C₁
  • Y-component: A₂ + B₂ + C₂

Conclusion of the Proof

Since both sides yield the same result, we can conclude that vector addition is indeed associative. This property is fundamental in vector algebra and is crucial for simplifying calculations in physics and engineering, where vectors are frequently used to represent forces, velocities, and other directional quantities.

In summary, the associative property of vector addition allows us to group vectors in any way we choose without affecting the outcome, making it a powerful tool in both theoretical and applied contexts.