Question 232: Laws of Motion

Question

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

Accepted Answer

Let upthrust of air be F
a
then
For downward motion of balloon
F
a
= mg Ã¢ÂÂ ma
mg Ã¢ÂÂ Fa = ma
For upward motion
$${F_a} - \left( {m - \Delta m} \right)g = \left( {m - \Delta m} \right)a$$
$$ \Rightarrow $$ $$\Delta m = {{2ma} \over {g + a}}$$

Answer

$${{2ma} \over {g + a}}$$

Answer

$${{2ma} \over {g - a}}$$

Answer

$${{ma} \over {g + a}}$$

Answer

$${{ma} \over {g - a}}$$

Laws of Motion

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

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