# USing el

Notes

•Using electricity **Useful energy** Definition - energy that performs the desired task in the right place and form. Examples include light from a lamp, movement of a car, and heat from a heater. **Wasted energy** Definition - energy that is not useful and disperses away, either going to the wrong place or at the wrong time. Examples include unwanted light, heat from machines, and sound (noise). Most wasted energy becomes heat (thermal energy). **Dissipation** Definition - when energy spreads into the surroundings and cannot be reused. Examples are a bulb producing both light and heat, and heat spreading into a room, representing wasted energy. **Friction & Resistance** Friction occurs when surfaces rub together, causing heat and slowing objects. Resistance happens in electrical wires, where electricity struggles to flow, producing heat and wasting energy. **Lubricants** Oil or grease spread between surfaces reduces friction, minimizes heat loss, and allows smoother movement. Insulation materials prevent heat from escaping, maintaining energy usefulness, such as in houses for warmth. **Efficiency** This measures how much energy is useful versus wasted....