Question

What are the changes that occur inside a helium balloon as it rises from sea level?

Answer 1

That (i) the volume of the balloon INCREASES......

Explanation:

And (ii) the density of the contained gas DECREASES.......

We assume a constant temperature, and thus `P_1V_1=P_2V_2`. And since `P_2"<<"P_1`, `V_2">>"V_1` in order to compensate for the pressure drop. Since `V_2` (and `V_1`) displaces a mass of air that is greater than the mass of the balloon, the balloon rises even higher in altitude.

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