There are five vectors,each of magnitude $8$ units. These vectors form a regular pentagon as shown in the figure. Find the magnitude of the resultant vector.

When $n$ vectors of different magnitudes are added,we get a null vector. Then the value of $n$ cannot be

The magnitude of the sum of two vectors $\vec{A}$ and $\vec{B}$ with $\theta$ as the angle between them is:

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.

The angle between two forces of equal magnitude $R$,if the magnitude of their resultant is $\frac{R}{2}$,is:

The vectors $\vec{A}$ and $\vec{B}$ are such that $|\vec{A}+\vec{B}|=|\vec{A}-\vec{B}|$. The angle between the two vectors is: (in $^{\circ}$)