An aircraft flew 4,000km in 5 hours. What was its average speed? Give you answer in km/hr.

The answer is 800km an hour

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.

The answer is c - the principal of original lateral continuity.