When the average kinetic energy of the molecules goes up (a rise in temperature), the average speed of the molecules increases. And lower average kinetic energy of the molecules means they have lower speed. However, a change in average kinetic energy is not directly proportional to a change in average speed. 1.
An appreciation means an increase in the value of a currency. It means a currency is worth more in terms of foreign currency.
By contrast, the one currency that has always had a higher value than the U.S. dollar, the British pound, has actually lost value against the U.S. dollar compared to the early 1970s and 1980s and it is the only najor currency to have a lower value against the U.S. dollar compared to early 2000.urthermore, the Australian dollar has also gained a higher value than the U.S. dollar. As a result there are now 5 major currencies with a higher value than the U.S. dollar, namely the British pound, the euro, the Swiss franc, the Canadian dollar and the Australian dollar.