Projectile Motion Questions

A missile is fired for maximum range with an initial velocity of $20\text{m/s}$. If $g=10{\text{m/s}}^2$, the range of the missile is:

A projectile is fired at $45^{\circ }$. Elevation angle of highest point from point of projection is:

The horizontal range and the maximum height of a projectile are equal. The angle of projection of the projectile is:

The velocity of a projectile at the initial point $A$ is $(2\hat{i}+3\hat{j})\text{m/s}$. Its velocity (in $\text{m/s}$) at point $B$ (the end of the trajectory on the same horizontal plane) is:

A projectile is fired from the surface of the earth with a velocity of $5\text{m/s}$ and angle $\theta$ with the horizontal. Another projectile fired from another planet with a velocity of $3\text{m/s}$ at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in ${\text{m/s}}^2$): (given $g=9.8{\text{m/s}}^2$)