Question

A balloon is moving vertically up with a velocity 4 m/s. When it is at a height h, a body is gently released from it. If it reached ground in 4 sec, the height of balloon, when the body is released, is

• A. 62.4 m
• B. 42.4 m
• C. 78.4 m
• D. 82.2 m

Answer 1

The correct option is C 78.4 m

$s=ut+\frac{1}{2}a{t}^2$
Therefore, $h=(0\times 4)+\left(0.5\right)\times 9.8\times 4\times 4$
h = 78.4 m