Answer: 200 knots
Explanation: the maximum indicated airspeed at which aircraft may be flown when at or below 2,500 feet AGL and within 4 nautical miles of the primary airport of Class C airspace is 200 KNOTS
First, we need to convert the pressure in SI units. Keeping in mind that

:

The initial and final volume of the gas are (keeping in mind that

):


So, the work done on the gas by the surrounding is

And the final positive sign means that this work corresponds to an increase in internal energy of the gas.
The two balls separate but continue to move in the same direction
Maybe the word could be converted?