Question

A particle has initial velocity $( 2 \vec{i} + 3 \vec{j})$ and acceleartion ($0 . 3 \vec{i} + 0 . 2 \vec{j})$ The magnitude of velocity after 10 seconds will be

• A. 9 $\sqrt 2$ units
• B. 5 $\sqrt 2$ units
• C. 5 units
• D. 9 units

Answer 1

Answer: (B)

5 $\sqrt 2$ units

Answer 2

$\vec{ v }=\overrightarrow{ u }+\vec{ a } t$
$\vec{ v }=(2 \hat{ i }+3 \hat{ j })+(0.3 \hat{ i }+0.2 \hat{ j }) \times 10$
$\Rightarrow \vec{ v }=5 \hat{ i }+5 \hat{ j }$
$v =5 \sqrt{2}$ units