Question

A person pushes a box kept on a horizontal surface with force of $100\, N$. In unit vector notation force can be expressed as

• A. $100(\hat{i}+\hat{j})$
• B. $100(\hat{i}-\hat{j})$
• C. $50 \sqrt{2}(\hat{i}-\hat{j})$
• D. $50 \sqrt{2}(\hat{i}+\hat{j})$

Answer 1

Answer: (C)

$\vec{F}=F \cos 45^{\circ} \hat{i}+F \sin 45^{\circ}(-\hat{j})$
$\Rightarrow \vec{F}=50 \sqrt{2} \hat{i}-50 \sqrt{2} \hat{j} N$