A boat is sent across a river with a velocity of $8\, km/hr$. If the resultant velocity of boat is $10 \,km/hr$, then velocity of the river is ........$km/hr$
If $\vec{A}+\vec{B}+\vec{C}=0$ then $\vec{A} \times \vec{B}$ is ............
A force of $5 N$ acts on a particle along a direction making an angle of $60^{\circ}$ with vertical. Its vertical component will be $.........\,N$
If the angle between two vectors $A$ and $B$ is $120^{\circ}$, its resultant $C$ will be
The vector sum of two forces is perpendicular to their vector differences. In that case, the force