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.
BREAKING DOWN 'Foreign Currency Effects' Foreign investments are complicated by currency fluctuation and conversion between countries. A high-quality investment in another country may prove worthless because of a weak domestic currency.