Question

A particle has an initial velocity of $7\hat{i}+24\hat{j}$ and an acceleration of $0.3\hat{i}+0.4\hat{j}$. Its speed after $10$ sec is

• A. 30 units
• B. 29.7 units
• C. 25 units
• D. $7\sqrt{2}$units

Answer 1

The correct option is B 29.7 units

Follow vector addotion for $\overrightarrow{v}=\overrightarrow{u}+\overrightarrow{a}t$

$\overrightarrow{u}=7\hat{i}+24\hat{j}$ and $\overrightarrow{a}t=3\hat{i}+4\hat{j}$

Hence $\overrightarrow{v}=10\hat{i}+28\hat{j}$