Y'= x.e^x/ (1+y).y giải pt vi phân cấp 1

1. Consider a hot pot taken off the stove and placed on a tile countertop. At first it cools quickly. As it cools, the difference in temperature between the pot and the room air becomes less, and so it takes a long time for the pot to lose enough heat to match room temperature. Two objects at the same temperature are said to be in equilibrium.

2.  When a liquid changes into a gas it absorbs energy. When it changes into a solid it gives off energy...If a solid (dry ice for example) is allowed to sublimate into a gas, it absorbs heat - that's why it feels cold when you touch ice. So, if a gas changes into a liquid, it give off heat as an opposite effect.  Anytime you compress a gas, it gets warmer.