Question

A particle has an initial velocity of $3\hat{i}+4\hat{j}$ and an acceleration of $0.4\hat{i}+0.3\hat{j}$. Its speed after $10s$ is?

Answer 1

the initial velocity is give as $vi=3i+4j$

the acceleration is $a=0.4i+0.3j$

and the time elapsed is$t=10s$

now final velocity after$10s$ is $v_f=(3i+4j)\frac{m}{s}+10s(0.4i+0.3j)\frac{m}{s}$

$v_f=7i+7j$

$v=\sqrt{\left(7i{)}^2\right)+\left(7j\right))}=7\sqrt{2}$