Question

a weather balloon slowly expands as energy is transferred as heat from the outside air. if the average net pressure is 1.5×10^5m^3, how much work is done by the expanding gas?

Answer 1

Answer:

W = $-8.1 * 10^{-2} J$

Explanation:

The rest of the question actually states that:

**If the average net pressure is 1.5x10^3Pa and the balloons volume increases by 5.4x10^-5 m^3, how much work is done by the expanding gas.**

Work done, W against an external pressure, $P_{ext}$, which causes a change in volume, ΔV of an object is given as:

$W = -P_{ext}$ ΔV

$P_{ext}$ = $1.5 * 10^5 Pa$

ΔV = $5.4 * 10^{-5} m^3$

=>  $W = -1.5 * 10^3 * 5.4 * 10^{-5}\\\\W = -8.1 * 10^{-2} J$

Note: The negative sign denotes that the work is done against external pressure.

Answer 2

There is only one pressure this situation would be a "constant pressure" process