$A$ particle is simultaneously acted upon by two forces equal to $4\, N$ and $3\, N$. The net force on the particle is

The sum of the magnitudes of two vectors acting at a point is $18$ and the magnitude of their resultant is $12$. If the resultant is at $90^{\circ}$ with the vector of smaller magnitude,then the magnitudes of the vectors are

$A$ truck travelling due north at $20 \, m/s$ turns west and travels at the same speed. The change in its velocity is

Two vectors $\overrightarrow{a}$ and $\overrightarrow{b}$ are at an angle of $60^{\circ}$ with each other. Their resultant makes an angle of $45^{\circ}$ with $\overrightarrow{a}$. If $|\vec{b}|=2$ units,then $|\vec{a}|$ is

Let $\vec{A}$ and $\vec{B}$ be two non-zero vectors of different magnitudes. Which one of the following is the correct equation?

$A$ body moves due East with a velocity of $20 \, km/h$ and then due North with a velocity of $15 \, km/h$. The resultant velocity is .......... $km/h$.