The trajectory of a projectile is given by `y=x tantheta-(1)/(2)(gx^(2))/(u^(2)cos^(2)theta)`. This equation can be used for calculating various phenomen such as finding the minimum velocity required to make a stone reach a certain point maximum range for a given projection velocity and the angle of projection required for maximum range. The range of a particle thrown from a tower is define as the distance the root of the tower and the point of landing.
From a certain tower of unknown height it is found that the maximum range at a certain projection velocity is obtained for a projection angle of `30^(@)` and this range is `10sqrt(3)m`. The projection velocity must be
A. `10m//s`
B. `10sqrt(3)m//s`
C. `(10)/(sqrt(3))m//s`
D. `5m//s`
