An NCC parade is travelling at a uniform speed of 6 km/h through a place under a berry tree, on which a bird is sitting at a height of 12.1 m . At a specific instant, the bird drops a berry. Determine the distance from the tree at that instant, in m, of the cadet who will receive the berry on his uniform.

Step-by-step solution

Speed of the cadet, v = 6 km/h = 6 5 18 m/s = 5 3 m/s Height of the bird, h = 12.1 m The initial velocity of the dropped berry is u = 0 . Using the equation of kinematics for the vertical motion of the berry: h = ut + 1 2 gt^2 12.1 = 0 + 1 2 (9.8)t^2 12.1 = 4.9t^2 t^2 = 12.1 4.9 = 121 49 t = 11 7 s The distance of the cadet from the tree at the instant the berry was dropped is equal to the distance travelled by the cadet during the time t . d = v t = 5 3 11 7 = 55 21 m d 2.62 m