SATHEE: Kinematics Question 604

Kinematics Question 604

Question: Let two vectors $\vec{A} = 3 \hat{i} + \hat{j} + 2 \hat{k}$

and $\vec{B} = 2 \hat{i} - 2 \hat{j} + 4 \hat{k}$ . Consider the unit vector perpendicular to both A and b is

Options:

A) $\frac{\hat{i} - \hat{j} - \hat{k}}{\sqrt{3}}$

B) $\frac{\hat{i} - \hat{j} - \hat{k}}{2 \sqrt{3}}$

C) $\frac{- \hat{i} - \hat{j} - \hat{k}}{\sqrt{3}}$

D) $\frac{\hat{i} - \hat{j} - \hat{k}}{2 \sqrt{3}}$

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Answer:

Correct Answer: A

Solution:

[a] Angle between $\vec{A}$ and $\vec{B}$

it’s given by $\cos θ = \frac{\vec{A} . \vec{B}}{AB} = \frac{3}{\sqrt{21}}$

The unit vector perpendicular to $\vec{A}$

and $\vec{B}$ it’s given by $\hat{n} = \frac{\vec{A} \times \vec{B}}{| \vec{A} \times \vec{B} |} = \frac{(3 \hat{i} + \hat{j} + 2 \hat{k}) \times (2 \hat{i} - 2 \hat{j} + 4 \hat{k})}{| (3 \hat{i} + \hat{j} + 2 \hat{k}) \times (2 \hat{i} - 2 \hat{j} + 4 \hat{k}) |}$

$= \frac{\hat{i} - \hat{j} - \hat{k}}{\sqrt{3}}$

Kinematics Question 604

Question: Let two vectors $\vec{A} = 3 \hat{i} + \hat{j} + 2 \hat{k}$

Options:

Answer:

Solution:

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Kinematics Question 604

Question: Let two vectors A→=3i^+j^+2k^

Options:

Answer:

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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Question: Let two vectors $\vec{A} = 3 \hat{i} + \hat{j} + 2 \hat{k}$