A particle is projected from ground with speed $80 \,m / s$ at angle $30^{\circ}$ with horizontal from ground. The magnitude of average velocity of particle in time interval $t=2 \,s$ to $t=6 \,s$ is ....... $m / s$ [Take $g=10 \,m / s ^2$ ]

A projectile is projected with kinetic energy $K$. If it has the maximum possible horizontal range, then its kinetic energy at the highest point will be ......... $K$

A particle of mass $100\,g$ is projected at time $t =0$ with a speed $20\,ms ^{-1}$ at an angle $45^{\circ}$ to the horizontal as given in the figure. The magnitude of the angular momentum of the particle about the starting point at time $t=2\,s$ is found to be $\sqrt{ K }\,kg\,m ^2 / s$. The value of $K$ is $............$ $\left(\right.$ Take $\left.g =10\,ms ^{-2}\right)$

For an object projected from ground with speed $u$ horizontal range is two times the maximum height attained by it. The horizontal range of object is ..........

A ball is projected with kinetic energy $E$ at an angle of ${45^o}$ to the horizontal. At the highest point during its flight, its kinetic energy will be

At the top of the trajectory of a projectile, the directions of its velocity and acceleration are