In the motion of a projectile freely under gravity, its

Two projectiles of same mass and with same velocity are thrown at an angle $60^o$ and $30^o$ with the horizontal, then which quantity will remain same

Two projectiles, one fired from surface of earth with velocity $10 \,m/s$ and other fired  from the surface of another planet with initial speed $5\, m/s$ trace identical trajectories.  The value of acceleration due to the gravity on the planet is   ......... $m/s^2$

Two objects are thrown up at angles of $45^{\circ}$ and $60^{\circ}$ respectively, with the horizontal. If both objects attain same vertical height, then the ratio of magnitude of velocities with which these are projected is .........

A ground to ground projectile is at point $A$ at $t=\frac{T}{3}$, is at point $B$ at $t=\frac{5 T}{6}$ and reaches the ground at $t=T$. The difference in heights between points $A$ and $B$ is

The equation of a projectile is $y =\sqrt{3} x -\frac{ gx ^2}{2}$ the angle of projection is