* Friction: Friction is the resistance to motion that occurs when two surfaces rub against each other. This can cause energy to be lost as heat.
* Air resistance: Air resistance is the resistance to motion that occurs when an object moves through the air. This can also cause energy to be lost as heat.
* Mechanical inefficiencies: There are a number of mechanical inefficiencies that can occur in machines, such as gears that don't mesh perfectly, bearings that don't roll smoothly, and belts that slip. These can all cause energy to be lost.
* Electrical inefficiencies: There are also a number of electrical inefficiencies that can occur in machines, such as resistance in wires, inefficiencies in transformers, and losses in capacitors. These can all cause energy to be lost.
* Thermal inefficiencies: There are also a number of thermal inefficiencies that can occur in machines, such as heat loss through radiation, convection, and conduction. These can all cause energy to be lost.
As a result of these inefficiencies, no machine is able to convert 100 percent of the energy it consumes into useful work.
