Laws Of Motion Question 430
Question: A balloon with mass M is descending down with an acceleration a (a < g). What mass’ of its contents must be removed so that it starts moving up with same acceleration a
Options:
A)$ \frac{2M( g )}{a} $
B) $ \frac{M( g+a )}{g} $
C)$ \frac{Mg}{g+a} $
D) $ \frac{2Ma}{g+a} $
Show Answer
Answer:
Correct Answer: D
Solution:
[d]
Up thrust F will remain same in both the cases.
Equations of motion be:
$ MgF=Ma $ …(1)
and$ F-(M-m)g=(M-m)a $ …(2)
solving equations (1) and (2) we get, mass to be removed $ m=\frac{2Ma}{g+a} $
