Chapter 3.1 Laws of Thermodynamics

Systems  A system is a set of interconnected parts  An open system is one that exchanges both matter and energy with its surroundings  A closed system is one that cannot exchange matter but can exchange energy with its surroundings  An isolated system is one that cannot exchange either matter or energy with its surroundings.

First Law of Thermodynamics  Work involves the movement of matter  Heat is a transfer of thermal energy  Energy can be increased in two ways… 1. heat can be added or 2. work can be done  First law of thermodynamics states that total energy in a system and its surroundings remains constant

Perfect Machines  If no energy is converted to other forms of energy, then the machine should continue to operate indefinitely. This is called a perfect machine or a perpetual motion machine.

2 nd Law of Thermodynamics  2 nd law states t hat heat always flows naturally from a hot object to a cold object.

Heat Engines  Heat pumps are devices that use mechanical energy to transfer heat  Heat engine is a device that converts heat into mechanical energy