alleryStart learning →The magnitude of the vector $\vec a = 4\hat i + 0\hat j + 3\hat k$ is:
- 5
- 7
- 12
- 25
Show answer and solution
Correct answer: A. 5
$|\vec a| = \sqrt{4^2 + 0^2 + 3^2} = \sqrt{25} = 5$.
KEAM Magnitude — practice questions
Explore 2 free Magnitude questions in KEAM Mathematics. Open each question or exercise to read its content, reference answers and available explanation.
Practise Magnitude with Quill →Magnitude questions and exercises with answers
Showing questions 1–2 of 2.
The magnitude of the vector $\vec a = 4\hat i + 0\hat j + 3\hat k$ is:Read the answer and worked solution →Vector $\vec a$ is directed due north with $|\vec a| = 24$ and vector $\vec b$ is directed due west with $|\vec b| = 7$. The magnitude $|\vec a + \vec b|$ equals:Read the answer and worked solution →
Worked practice questions
Vector $\vec a$ is directed due north with $|\vec a| = 24$ and vector $\vec b$ is directed due west with $|\vec b| = 7$. The magnitude $|\vec a + \vec b|$ equals:
- 17
- 25
- 31
- $\sqrt{527}$
Show answer and solution
Correct answer: B. 25
North and west are perpendicular, so $|\vec a + \vec b| = \sqrt{|\vec a|^2 + |\vec b|^2} = \sqrt{576 + 49} = \sqrt{625} = 25$.
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