\
For adiabatic expansion, the pressure
and volume
are related by the equation
, where
is a constant.
At an instant, volume
and the pressure
.
Rate of change of pressure
.
Here the negative sign indicates that the pressure is decreasing.
\Consider
.
Differentiate on each side with respect to
.

Substitute
and
in the above equation.

Therefore, the volume is increasing at a rate of
cm3/min.
\
The volume is increasing at a rate of
cm3/min.