The equation of motion of a projectile are given by $ x = 36 t\,metre$ and $2y = 96 t -9.8 t^2\, metre$. The angle of projection is
${\sin ^{ - 1}}\left( {\frac{4}{5}} \right)$
${\sin ^{ - 1}}\left( {\frac{3}{5}} \right)$
${\sin ^{ - 1}}\left( {\frac{4}{3}} \right)$
${\sin ^{ - 1}}\left( {\frac{3}{4}} \right)$
A ball of mass $1 \;kg$ is thrown vertically upwards and returns to the ground after $3\; seconds$. Another ball, thrown at $60^{\circ}$ with vertical also stays in air for the same time before it touches the ground. The ratio of the two heights are
A water fountain on the ground sprinkles water all around it. If the speed of water coming out of the fountain is $v$, the total area around the fountain that gets wet is :
At what angle the particle should be projected to cover maximum range ?
Two bodies are thrown up at angles of $45^o$ and $60^o$, respectively, with the horizontal. If both bodies attain same vertical height, then the ratio of velocities with which these are thrown is
Figure shows a projectile thrown with speed $u=20 \,m / s$ at an angle $30^{\circ}$ with horizontal from the top of a building $40 \,m$ high. Then the horizontal range of projectile is ........... $m$