A body is projected from the top of a tower with a velocity
−
u
=3
⋀
i
+4
⋀
j
+5
⋀
k
ms−1, where
⋀
i
,
⋀
j
and
⋀
k
are unit vectors along east, north and vertically upwards respectively. If the height of the tower is 30 m. horizontal range of the body on the ground is (g=10ms2)
Given Data: u=5m∕s a=−10m∕s2 h=−30m The figure below represents the projectile motion.
h=ut+
1
2
at2 −30=5t−
1
2
×10×t2 By solving the above equation. t=3 or t≠−2 t=3s The distance covered in east direction is, dx=3×3=9m The distance covered in north direction is, dy=4×3=12m