Two vectors $\vec{A}$ and $\vec{B}$ have magnitudes $3 \text{ units}$ and $4 \text{ units}$ respectively. If the angle between them is $60^{\circ}$,find the magnitude of their resultant vector.

$A$ car travels $6 \, km$ at an angle of $45^\circ$ north of east and then travels $4 \, km$ at an angle of $135^\circ$ north of east. How far is the final point from the starting point? What angle does the straight line joining its initial and final position make with the east?

The resultant force of $5 \, N$ and $10 \, N$ cannot be ........ $N$.

Statement $I:$ Two forces $(\overrightarrow{P}+\overrightarrow{Q})$ and $(\overrightarrow{P}-\overrightarrow{Q})$,where $\overrightarrow{P} \perp \overrightarrow{Q}$,act at an angle $\theta_{1}$ to each other,and the magnitude of their resultant is $\sqrt{3(P^{2}+Q^{2})}$. When they act at an angle $\theta_{2}$,the magnitude of their resultant becomes $\sqrt{2(P^{2}+Q^{2})}$. This is possible only when $\theta_{1} < \theta_{2}$.
Statement $II:$ In the situation given above,$\theta_{1} = 60^{\circ}$ and $\theta_{2} = 90^{\circ}$.
In the light of the above statements,choose the most appropriate answer from the options given below.

Are the magnitude and direction of $\vec{A} - \vec{B}$ and $\vec{B} - \vec{A}$ the same?

If $r_1=2 \hat{x}$ and $r_2=2 \hat{y}$, where $\hat{x}$ and $\hat{y}$ are unit vectors along the $X$-axis and $Y$-axis respectively, then the magnitude of $r_1+r_2$ is