JEE Main & Advanced Physics Two Dimensional Motion JEE PYQ - Two Dimensional Relative Motion

A particle has an initial velocity of\[3\hat{i}+4\hat{j}\]and an acceleration of\[0.4\hat{i}+0.3\hat{j}\]. It speed after 10 s is: [AIEEE 2009]

A) 10 units

B) \[7\sqrt{2}\] units

C) 7 units

D) 8.5 units.

Correct Answer: B

Solution :

[b] \[\overrightarrow{V}=\overrightarrow{u}+\overrightarrow{at}\]

\[\overrightarrow{V}=(3\hat{i}+4\hat{j})+10(0.4\hat{i}+0.3\hat{j})\]

\[\overrightarrow{V}=7\widehat{i}+7\hat{j}\]

\[\Rightarrow \] \[|\overrightarrow{V}|=7\sqrt{2}\]