A projectile is fired at the top of a building at an angle of 20° below the horizontal. If the muzzle velocity of the projectile is 8 m/s, how high is the building if the projectile reaches the ground after 3sec.
The equation to solve for time of the freight is a quadratic equation and is given as follows for object thrown at an angle below the horizontal.
u, T and angle are given in the question. The same are substituted to obtain height of the building.