Maslow's Hierarchy of Needs. Definition. Maslow's hierarchy of needs is a theory of motivation and personality developed by the psychologist Abraham H. Maslow (1908â1970). Maslow's hierarchy explains human behavior in terms of basic requirements for survival and growth.
When you use ice to cool the ingredients for ice cream, the energy is absorbed from the ingredients and from the outside environment (like your hands, if you are holding the baggie of ice!).
Ice is at a temperature of 0 ï°C; the surroundings are at about 20 ï°C. For ice to melt, it must gain energy from the surroundings. Energy can be transferred (move) from the surroundings to the ice by conduction through the metal or plastic. Metal is a better conductor than plastic, so energy is transferred more quickly through the metal.