  We have used the AMR hydrodynamic code, MG, to perform 3D magnetohydrodynamic
simulations with self-gravity of stellar feedback in a sheet-like molecular
cloud formed through the action of the thermal instability. We simulate the
interaction of the mechanical energy input from a 15 solar mass star and a 40
solar mass star into a 100 pc-diameter 17000 solar mass cloud with a corrugated
sheet morphology that in projection appears filamentary. The stellar winds are
introduced using appropriate Geneva stellar evolution models. In the 15 solar
mass star case, the wind forms a narrow bipolar cavity with minimal effect on
the parent cloud. In the 40 solar mass star case, the more powerful stellar
wind creates a large cylindrical cavity through the centre of the cloud. After
12.5 Myrs and 4.97 Myrs respectively, the massive stars explode as supernovae
(SNe). In the 15 solar mass star case, the SN material and energy is primarily
deposited into the molecular cloud surroundings over ~10^5 years before the SN
remnant escapes the cloud. In the 40 solar mass star case, a significant
fraction of the SN material and energy rapidly escapes the molecular cloud
along the wind cavity in a few tens of kiloyears. Both SN events compress the
molecular cloud material around them to higher densities (so may trigger
further star formation), and strengthen the magnetic field, typically by
factors of 2-3 but up to a factor of 10. Our simulations are relevant to
observations of bubbles in flattened ring-like molecular clouds and bipolar HII
regions.
