| The movement of energy from one form or place to another, such as from one energy store to another. | Energy Transfer |
| What happens to energy during an energy transfer? | Energy is moved from one energy store to another, either within the same object or between different objects. |
| The extent to which energy can be harnessed to perform work or tasks that are beneficial or desired. | Usefulness of Energy |
| How is energy transferred in an electric scooter? | In an electric scooter, energy is transferred from the battery's chemical energy store to the scooter's kinetic energy store when it is switched on. |
| Energy that is transferred to less useful energy stores, often resulting in energy loss or waste. | Dissipated Energy |
| What happens to some of the energy in an electric scooter when it is in use? | Some of the energy in the electric scooter is dissipated, transferring to less useful energy stores such as thermal energy, resulting in energy loss. |
| Different forms or locations in which energy can be held or stored within a system, including kinetic, potential, chemical, thermal, and others. | Energy Stores |
| Where is energy stored in an electric scooter before it is used? | In an electric scooter, energy is stored in the battery's chemical energy store before it is used to power the scooter. |
| The internal energy of an object due to the motion of its atoms and molecules, associated with heat. | Thermal Energy |
| What happens to some of the dissipated energy in an electric scooter? | Some of the dissipated energy is transferred to the thermal energy stores of the scooter and its surroundings, increasing the temperature. |
| Energy that is not effectively utilized for useful work and is instead lost to the surroundings in the form of heat or other less useful forms. | Wasted Energy |
| Why is some energy in an electric scooter considered wasted? | Some energy in an electric scooter is considered wasted because it is transferred to less useful energy stores, such as thermal energy, rather than being fully utilized for useful work like propulsion. |
| Energy that is transferred to less useful energy stores, resulting in energy loss or waste. | Dissipated Energy |
| What happens to energy during dissipation? | Energy is transferred to less useful energy stores, such as thermal energy, rather than being utilized for useful work. |
| Energy that is not effectively utilized for useful work and is instead lost to the surroundings in less useful forms, such as heat. | Wasted Energy |
| What is meant by "wasted energy" in a system change? | Wasted energy refers to energy that is transferred to less useful energy stores during a system change, leading to energy loss. |
| Processes involving the movement or interaction of mechanical components, such as gears, levers, or surfaces sliding past each other. | Mechanical Processes |
| Why are mechanical processes often considered wasteful? | Mechanical processes are often considered wasteful because they can lead to a rise in temperature due to friction, resulting in dissipation of energy as heat. |
| The resistance encountered when one surface moves or tries to move past another surface, resulting in the conversion of mechanical energy into thermal energy. | Friction |
| What role does friction play in the dissipation of energy? | Friction between surfaces moving past each other leads to the conversion of mechanical energy into thermal energy, resulting in the dissipation of energy. |
| The internal energy of an object due to the motion of its atoms and molecules, associated with heat. | Thermal Energy |
| How is dissipated energy often manifested in mechanical processes? | Dissipated energy in mechanical processes is often manifested as an increase in the temperature of the system and its surroundings, due to the conversion of mechanical energy into thermal energy. |
| The ratio of useful energy output to total energy input, expressed as a percentage. | Efficiency of Energy Transfer |
| How is the efficiency of an energy transfer calculated? | The efficiency of an energy transfer is calculated by dividing the useful energy output by the total energy input and multiplying by 100%. |
| Energy that is effectively utilized for a desired purpose or task within a system or process. | Useful Energy |
| What constitutes useful energy in an energy transfer process? | Useful energy is the energy that is successfully transferred to perform a desired task or function, contributing to the intended output of the system. |
| Energy that is lost or wasted during an energy transfer process, typically converted into less useful forms such as heat. | Dissipated Energy |
| What happens to energy that is dissipated during an energy transfer? | Energy that is dissipated during an energy transfer is lost to the surroundings as waste heat or other less useful forms, reducing the overall efficiency of the process. |
| The mathematical expression used to calculate the efficiency of an energy transfer, expressed as the ratio of useful energy output to total energy input. | Efficiency Equation |
| For example, if 50 J of energy are supplied to a light bulb and 10 J are usefully transferred, the efficiency of the bulb is calculated like this: | Example Calculation |
| How does reducing dissipated energy affect the efficiency of an energy transfer? | Reducing dissipated energy leads to an increase in the efficiency of an energy transfer, as more energy is effectively utilized for useful purposes rather than being lost as waste. |
| Material or technology used to reduce the transfer of heat energy between objects or environments, thereby minimizing energy loss. | Thermal Insulation |
| How does thermal insulation contribute to increasing energy transfer efficiency in heating systems? | Thermal insulation reduces heat loss by limiting the transfer of thermal energy through walls or barriers, thereby increasing the efficiency of heating systems by minimizing wasted energy. |
| The process of minimizing the dissipation of energy during an energy transfer, aimed at improving overall efficiency. | Energy Loss Reduction |
| Why are systems never 100% efficient in energy transfers? | Systems are never 100% efficient in energy transfers because some energy is inevitably dissipated as waste, reducing the overall efficiency of the process. |
