

InterviewSolution
Saved Bookmarks
1. |
A balloon with mass `m` is descending down with an acceleration a `(where altg)` . How much mass should be removed from it so that it starts moving up with an acceleration a? |
Answer» Correct Answer - `(2Ma)/(g +a)` . Let`F` be the upthrust of air in either case In(i) case, `Mg - F = Ma` …(i) In (ii) case `F - (M -m) g = (M - m) a` …(ii) using (i) `(Mg - Mg) - Mg + mg = Ma - ma` or `m (g +a) = 2 Ma` `m = (2Ma)/(g + a)` . |
|