<span>Melting of ice is an endothermic process, meaning that energy is absorbed. When ice spontaneously melts, ΔH (change in enthalpy) is "positive". ΔS (entropy change) is also positive, because, becoming a liquid, water molecules lose their fixed position in the ice crystal, and become more disorganized. ΔG (free energy of reaction) is negative when a reaction proceeds spontaneously, as it happens in this case. Ice spontaneously melts at temperatures higher than 0°C. However, liquid water also spontaneously freezes at temperatures below 0°C. Therefore the temperature is instrumental in determining which "melting" of ice, or "freezing" of water becomes spontaneous. The whole process is summarized in the Gibbs free energy equation:
ΔG = ΔH – TΔS</span>
Answer:
So airplane will be 1324.9453 m apart after 2.9 hour
Explanation:
So if we draw the vectors of a 2d graph we see that the difference in angles is = 83 - 44.3 = 
Distance traveled by first plane = 730×2.9 = 2117 m
And distance traveled by second plane = 590×2.9 = 1711 m
We represent these distances as two sides of the triangle, and the distance between the planes as the side opposing the angle 38.7.
Using the law of cosine,
representing the distance between the planes, we see that:

d = 1324.9453 m
Is limited in scope and was discovered during a study of epilepsy
Hope this works xoxo