SATHEE: Kinematics Question 428

Kinematics Question 428

Question: Two forces ${\vec{F}}_{1} = 10 \hat{i} - \hat{j} - 15 \hat{k}$ and ${\vec{F}}_{2} = 10 \hat{i} - \hat{j} - 15 \hat{k}$ act on a single point. The angle between ${\vec{F}}_{1}$ and ${\vec{F}}_{2}$ it’s nearly

Options:

A) $30^{o}$

B) $45^{o}$

C) $60^{o}$

D) $90^{o}$

Show Answer

Answer:

Correct Answer: B

Solution:

[b] $\cos θ = \frac{{\vec{F}}_{1} . {\vec{F}}_{2}}{| {\vec{F}}_{1} | | {\vec{F}}_{2} |}$ $= \frac{(5 \hat{i} + 10 \hat{j} - 20 \hat{k}) \cdot (10 \hat{i} - 5 \hat{j} - 15 \hat{k})}{\sqrt{25 + 100 + 400} \cdot \sqrt{100 + 25 + 225}}$ $= \frac{50 - 50 + 300}{\sqrt{525} \cdot \sqrt{350}}$

$\Rightarrow$ $\cos θ = \frac{1}{\sqrt{2}}$

$∴$ $θ = 45^{o}$

Kinematics Question 428

Question: Two forces ${\vec{F}}_{1} = 10 \hat{i} - \hat{j} - 15 \hat{k}$ and ${\vec{F}}_{2} = 10 \hat{i} - \hat{j} - 15 \hat{k}$ act on a single point. The angle between ${\vec{F}}_{1}$ and ${\vec{F}}_{2}$ it’s nearly

Options:

Answer:

Solution:

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Kinematics Question 428

Question: Two forces F→1=10i^−j^−15k^ and F→2=10i^−j^−15k^ act on a single point. The angle between F→1 and F→2 it’s nearly

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: Two forces ${\vec{F}}_{1} = 10 \hat{i} - \hat{j} - 15 \hat{k}$ and ${\vec{F}}_{2} = 10 \hat{i} - \hat{j} - 15 \hat{k}$ act on a single point. The angle between ${\vec{F}}_{1}$ and ${\vec{F}}_{2}$ it’s nearly