An NCC parade is going 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 particular instant the bird drops a berry. Which cadet (ie the distance from the tree at the instant) will receive the berry on his uniform?

Answer

D

Explanation

Let the true time of fall be t
Initial velocity
y=0
Acceleration = `9.8 m/s^2
Distance S= 12.1 m
:. Sut+ 1/2 at^2
rarr 12.1= 0+1/2 xx 9.8 t^2
rarr t^2 = 12.1/4.9=2.46
rarrt= 1.57 sec`
For cadet velocity `= 6 km/hr=1.66 m/sec` Distance = vt= 1.57xx1.66=2.6m`
The cadet 2.6 m, away from tree will receive the berry on his uniform.