The answer is
Pitch of the buzzer increased (higher tone) as it moves towards the observer
Turn lights off, unplug electronics, and use solar energy
Explanation:
The angular momentum is doubled because it is proportional to the angular velocity.
From Boyle's law, the volume of a fixed mass of a gas is inversely proportional to its pressure at constant absolute temperature.
Therefore; P1V1 =P2V2; where PV is a constant
hence; 12 × 6 = 3× p2
p2 = 72/3
= 24 atm
Therefore; the new pressure will be 24 atm
Use the impulse-momentum theorem.

Substitute your known values:

Hope this helps!