AP EAMCET202018 Sep 2020Evening ShiftPhysicsLaws of MotionActual
A balloon of mass (M ) descends with an acceleration (a( < g) ). What mass need to be removed from the balloon, so that it starts ascending with acceleration, (a ) ?
Options
- A( 2 M (a+g) )
- B( 2 M a (a+g) )
- C( 2 M a (a-g) )
- D( 2 M a (g-a) )
Correct answer
B. ( 2 M a (a+g) )
Step-by-step solution
The given situation is shown in the figure In above figures, (M ) is the mass of balloon and (M^ ) is the mass remove from the ballon. According to Newton's law of motion in first case, (M g-F=M a F=M g-M a ) ...(i) According to Newton's second law of motion, for second case, ( aligned & F- (M-M^ ) g= (M-M^ ) a & F-M g+M^ g=M a-M^ a & M g-M a-M g+M^ g=M a-M^ a [from Eq. (i)] & M^ g+M^ a=M a+M a & M^ (g+a)=2 M a & M^ = 2 M a g+a aligned )