Energy Transfer and Transformation
Energy is the ability to produce change. Change produced by energy can involve the substance’s change of state, the emission of light, the emission of heat, or the movement of an object.
Different forms of energy play a role in the functioning of technological systems. Here are the main forms of energy covered in the Secondary Cycle 1.
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In the Secondary Cycle 2, chemical energy, nuclear energy, and electrical energy are also covered.
Energy Transformation
Many devices or technological systems used in our everyday life are powered by electrical energy. They can simply be plugged into an electrical outlet in order to function.
When a system is in operation, one or more components can transform the electrical energy consumed into another form of energy.
Energy transformation is the conversion of energy from one form to another.
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Energy transformation is different from energy transfer.
Identifying Energy Transformations in a Technological System
To identify the transformation of energy in a technological system, we must observe the system in operation and look for one or more of the following changes to occur, and then associate them with the corresponding form of energy.
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An emission of light or radiation is associated with radiant energy;
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A release of heat is associated with thermal energy;
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Motion is associated with mechanical energy.
What is the energy transformation carried out by a compact fluorescent light bulb when we turn the switch on?
Transformation of energy by a compact fluorescent bulb
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To turn on a food processor, it must be plugged into an electrical outlet. Once the food processor is running, a motor drives the blade in a rotational motion.
What is the energy transformation performed by the motor of the food processor?
The transformation of energy in a food processor
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A single technological system can perform several energy transformations.
In a toaster’s technological system, our focus is on the heating element. For the toaster to operate, it must be plugged into an electrical outlet.
Energy transformations in a toaster
The toaster consumes electrical energy, because it must be plugged into an electrical outlet to operate.
The toaster's heating element gives off heat, which toasts the slices of bread. In addition, the heating element emits red light. These are two indicators of energy transformation to thermal energy (heat) and radiant energy (light). It can, therefore, be said that the heating element of the toaster transforms electrical energy into thermal energy and radiant energy.
Energy Transfer
Energy transfer is the movement of energy from one environment to another while retaining its form.
When a cyclist applies sufficient force to each pedal, it turns in a rotational motion. The motion is associated with mechanical energy. The mechanical energy is then transferred to the rear wheel to move the bike forward.
The energy remains in mechanical form during the transfer from the pedal to the rear wheel. It is therefore a transfer of mechanical energy.
The transfer of mechanical energy in a bicycle
When we place a pot of soup on the flame of a gas stove, the soup absorbs heat. The heat generated by the flame is transferred to the pot and then to the soup.
The energy remains in thermal form during the transfer from the flame to the soup. It is, therefore, a transfer of thermal energy.
The transfer of thermal energy from a flame to a pot of soup