A ballon with mass 'm’ is descending down with an acceleration ‘a' (where a le g). How much mass should be removed from it so that is starts moving up with an acceleration ‘a ’ ?

A ballon with mass 'm’ is descending down with an acceleration ‘a'

1.	A ballon with mass 'm’ is descending down with an acceleration ‘a' (where a le g). How much mass should be removed from it so that is starts moving up with an acceleration ‘a ’ ?
Answer» `(2ma)/(G+a)` `(2ma)/(g-a)` `(ma)/(g+a)` `(ma)/(g-a)` SOLUTION : from FIGURE (2) F- (m-m) g= (m-m) a wherem= m - m mg - ma - mg + mg = ma = m a mg+ma = ma m(g + a ) = 2 ma `m= (2ma )/( g+ a)`