Question

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

• A. 7 units
• B. 8.5 units
• C. 10 units
• D. $7\sqrt{2}$

Answer 1

The correct option is D $7\sqrt{2}$

along x axis

$v_x=u_x+a_{x}t3+\left(0.4\right(10\left)\right)=7m/secalongYaxis{v}_y=u_y+a_{y}t=4+\left(0.3\right(10\left)\right)=7m/sec{v}_{net}=\sqrt{v_x^2+v_y^2}=7\sqrt{2}units$