Question

A man in a balloon rising vertically with an acceleration of $4.9m/se{c}^2$ releases a ball $2$ sec after the balloon is let go from the ground. The greatest height above the ground reaches by the ball is $(g=9.8m/se{c}^2)$

• A. $14.7m$
• B. $19.6m$
• C. $9.8m$
• D. $24.5m$

Answer 1

The correct option is A $14.7m$

$a=4.9㎨$

Initial velocity $=0$

Velocity of balloon and ball after $2$ sec

$v=u+at=9.8㎧$

Height at this point

$h=\frac{1}{2}a{t}^2$

$=0.5\times 4.9\times 4$

$=9.8m$

The ball will attain further height $=s$

$\frac{1}{2}m{v}^2=mgs$

$s=\frac{v^2}{2g}=4.9m$

Greatest height that can be achieved

$H=h+s=9.8+4.9=14.7m$