- In other words the amount of energy put into a system must equal the amount of mechanical energy output __ The Second Law of Thermodynamics states that __ B3.2 Development of Engine Technology - Read p. 206- 214 in textbookVideo -Enrly Theories of Heat Video-Steam Engine History B3.3 Useful Energy and Efficiency pages 215-220 Useful Energy - The purpose of a machine is to convert the initial energy input to the type of desired energy output. Energy input refers to the __ Useful energy output refers to the __

- In other words, the amount of energy put into a system must equal the amount of mechanical energy output **if there are no energy losses due to friction or other factors. This principle embodies the Law of Conservation of Energy (also known as the First Law of Thermodynamics).**<br /><br />The Second Law of Thermodynamics states that **natural processes tend to proceed in a direction that increases the total entropy (disorder) of the universe. It also states that it is impossible to convert heat completely into work in a cyclical process.** Another way to express this is that no heat engine can be 100% efficient.<br /><br />B3.2 Development of Engine Technology - Read p. 206-214 in textbook Video - Early Theories of Heat Video - Steam Engine History<br /><br />B3.3 Useful Energy and Efficiency pages 215-220<br />Useful Energy<br /><br />- The purpose of a machine is to convert the initial energy input to the type of desired energy output. Energy input refers to the **total energy supplied to the machine to make it operate.** This could be in various forms like chemical energy (fuel), electrical energy, or mechanical energy.<br /><br />Useful energy output refers to the **energy delivered by the machine in the desired form and that accomplishes the intended task.** For example, the useful energy output of a light bulb is light energy, while for an electric motor, it's mechanical energy.<br />