Question

A person pushes a box kept on a horizontal surface with force of $100N$. 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)

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