Answer:
The ball reaches Barney head in 
Explanation:
From the question we are told that
The rise velocity is 
The height considered is 
The horizontal velocity of the large object is 
Generally from kinematic equation

Here s is the distance of the object from Barney head ,
u is the velocity of the object along the vertical axis which is equal but opposite to the velocity of the helicopter
So

So

= 
Solving the above equation using quadratic formula
The value of t obtained is 
A surface in which is flat or very soft to the touch and reduces splinters or anything sticking out, having an surface which does not have lumps, or indentations.
Answer:
Option (D) is correct.
Explanation:
The balloon lands horizontally at a distance of 420 m from a point where it as released.
Velocity of air balloon along +X axis =10 m/s
velocity of ball=4 m/s along + X axis
the velocity of balloon gets added to the velocity of ball. So the resultant velocity of the balloon=10+4 = 14 m/s
time taken= 30 s
The distance traveled is given by d= v t
d= 14 (30)
d= 420 m
Thus the balloon lands horizontally at a distance of 420 m from a point where it as released.