Q.

A balloon and its content having mass M is moving up with an acceleration 'a'. The mass that must be released from the content so that the balloon starts moving up with an acceleration '3a' will be: (Take 'g' as acceleration due to gravity)          [2025]

1 3Ma2ag  
2 3Ma2a+g  
3 2Ma3a+g  
4 2Ma3ag  

Ans.

(3)

FMg=Ma  F=Ma+Mg          ... (i)

F(Mx)g=(Mx)3a                        ... (ii)

From (i) and (ii)

Ma+MgMg+xg=3Ma3xa  x=2Mag+3a