Question

From a balloon rising vertically upwards as $5\,m/s$ a stone is thrown up at $10 \,m/s$ relative to the balloon. Its velocity with respect to ground after $2\,s$ is (assume $g=10\,m/s^{2}$ )

• A. zero
• B. $5\, m/s$
• C. $10\,m/s$
• D. $20\,m/s$

Answer 1

Answer: (B)

$5\, m/s$

Answer 2

The initial velocity with respect to ground will be $10+5=15 m / s$
after 2 sec its velocity will be $v =15- gt =15-10 \times 2=-5 m / s$
Whose value is $5 m / s$
Once the stone is projected from balloon it will not have any impact of the balloon after that moment.