Conservation of energy Study Guide

Efficiency refers to the ratio of useful energy output to total energy input, often expressed as a percentage. In any system, some energy is inevitably wasted, usually as heat or sound, due to processes like friction, electrical resistance, or air resistance. To increase efficiency means to reduce the amount of wasted energy, thereby maximising the proportion of energy converted into the desired form. This can be achieved through various methods. For mechanical systems, reducing friction through lubrication, or streamlining designs to minimise air resistance, are effective strategies. For electrical systems, using conductors with lower resistance or components designed for minimal heat loss improves efficiency. Insulating components can also prevent useful thermal energy from escaping or unwanted thermal energy from entering. Ultimately, increasing efficiency conserves energy resources and reduces operational costs.

Kinetic energy (KE) is the energy an object possesses due to its motion. Any object that is moving has kinetic energy. The amount of kinetic energy depends on two factors: the object's mass and its speed. A heavier object moving at the same speed will have more kinetic energy than a lighter object. Similarly, an object moving at a higher speed will have significantly more kinetic energy than the same object moving at a lower speed, as speed is squared in the kinetic energy equation. This energy is measured in joules (J).