Answers

2015-06-24T11:50:24+05:30
After the stone is dropped, 
acceleration of stone(a_s) = -9.8 m/s²
acceleration of balloon(a_b) = +0.2 m/s²

relative acceleration of balloon with respect to stone
a_b-a_s
= +0.2 - (-9.8)
= +0.2 + 9.8
= +10 m/s²

Relative acceleration of balloon wrt the stone is 10 m/s² upward. (+ sign is for upward direction)

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