The height $y$ and the distance $x$ along the horizontal plane of a projectile on a certain planet (with no surrounding atmosphere) are given by $y = 8t - 5t^2 \text{ m}$ and $x = 6t \text{ m}$,where $t$ is in seconds. The velocity with which the projectile is projected is (in $\text{ m/s}$)

$A$ ball is thrown from a point on the ground at some angle of projection. At the same time,a bird starts from a point directly above this point of projection at a height $h$ and moves horizontally with speed $u$. Given that in its flight,the ball just touches the bird at one point. Find the distance on the ground where the ball strikes.

The range of the projectile projected at an angle of $15^{\circ}$ with the horizontal is $50\,m$. If the projectile is projected with the same velocity at an angle of $45^{\circ}$ with the horizontal,then its range will be $........\,m$.

One second after projection, a projectile is travelling in a direction inclined at $45^{\circ}$ to the horizontal. After two more seconds, it is travelling horizontally. Then the magnitude of the initial velocity of the projectile is $(g = 10 \,ms^{-2})$

$A$ person can throw a ball up to a maximum range of $100 \, m$. How high above the ground can he throw the same ball (in $, m$)?

$A$ ball is thrown from the ground to clear a wall $3 \, m$ high at a distance of $6 \, m$ and falls $18 \, m$ away from the wall. The angle of projection of the ball is: