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.
1 This means your dollar will buy more of another foreign currency so that you can purchase foreign goods. 2  For example, if you were traveling and shopping in Europe and the exchange rate of the dollar vs. euro went from (0.75 to 1) to (0.95 to 1) your dollars would now buy more Euros. lower or weak exchange rate can have the opposite effect as a strong exchange rate or currency. Let's discuss those now. 1  Imports more expensive: If the dollar or your own currency declines, this erodes the value of your personal finances.