A distress flare is fired from the ground such that it reaches a maximum vertical height of 21.6 m . If the angle of projection was 60^ with the horizontal, what was the initial speed of the flare? (Take g = 10 m/s ^2 and neglect air resistance)

Step-by-step solution

The maximum height H of a projectile is given by the formula: H = u^2 ^2 2g Substituting the given values H = 21.6 m , = 60^ , and g = 10 m/s ^2 : 21.6 = u^2 ^2 60^ 2 10 21.6 = u^2 ( 3 2 )^2 20 21.6 = 3u^2 80 u^2 = 21.6 80 3 u^2 = 1728 3 = 576 u = 24 m/s Answer: 24 m/s