A projectile is thrown with velocity $u$ making angle $\theta$ with vertical. It just crosses the tops of two poles each of height $h$ after $1\,s$ and $3\,s$, respectively. The maximum height of projectile is ............ $m$
$9.8$
$19.6$
$39.2$
$4.9$
For a projectile the ratio of maximum height reached to the square of flight time is
A stone is projected in air. Its time of flight is $3\,s$ and range is $150\,m$ Maximum height reached by the stone is $......\,m$ $\left(g=10\,ms ^{-2}\right)$
The initial velocity of a particle of mass $2\,kg$ is $(4 \hat{ i }+4 \hat{ j })\,m / s$. A constant force of $-20 \hat{ j }\,N$ is applied on the particle. Initially, the particle was at $(0,0)$. Find the $x$-coordinate of the point where its $y$-coordinate is again zero.$..........\,m$
Two projectiles $A$ and $B$ are thrown with the same speed such that $A$ makes angle $\theta$ with the horizontal and $B$ makes angle $\theta$ with the vertical, then
If the time of flight of a bullet over a horizontal range $R$ is $T$, then the angle of projection with horizontal is ......