Transformation of energy in the car, simple electric cell, electric lamp, positive and negative effects of technology
An electric current is generated when copper wire & zinc rod are dipped inside a lemon after connecting them with an electric lamp because the chemical energy stored in the lemon is converted into electric energy, When two different metals connected with a compass are dipped in a lemon, the needle of compass deflects due to flowing of an electric current.
Transformation of Energy in the simple electric cell
In the simple electric cell, the chemical energy changes into electric energy, To make a model of the simple electric cell: The tools are a large lemon, a small compass, a copper wire, and a zinc rod.
Press the lemon to soften it and to increase its juice, Make the two terminals (ends) of the copper wire uncovered, Coil one of the uncovered terminal of the copper wire around the zinc rod, then dip the zinc rod into the lemon, Coil the wire around the compass, then dip the other uncovered terminal into the lemon.
The needle of the compass deflects, Some chemical reactions occur inside the lemon producing an electric current that is indicated by the deflection of the compass needle, The chemical energy stored in the lemon is converted into electric energy as in the simple electric cell.
If a potato is used instead of the lemon, The needle of the compass will deflect due to the production of the electric current, because a potato has a salt solution that has the same role of an acidic solution of lemon in completing the reaction.
The simple electric cell
Simple electric cell converts the chemical energy into electric energy, It consists of a glass container containing dilute sulphuric acid (H2SO4), Two metal plates are immersed (dipped) in the diluted sulphuric acid and connected to each other, one of them is copper (positive pole) and the other is zinc (negative pole).
The electric current passes from the positive copper plate (+) to negative zinc plate (−), Immersing two copper plates in diluted sulphuric acid is not considered a simple electric cell because the simple electric cell must have two different metal plates immersed in diluted sulphuric acid.
Transformation of energy in the electric lamp
In the electric lamp, electric energy changes into light energy & heat energy, The tools are a battery (dry electric cell), An electric lamp, connecting wires, and a switch, Connect the electric circuit, Close the circuit for one minute, then open it again, Touch the glass of the lamp with your hand, the lamp lights and becomes hot.
Passing the electric current in the filament of the electric lamp makes it hot & glows up, The electric current flows through the closed electric circuit, In the electric lamp, the electric energy changes into light energy and heat energy.
Using the batteries in the electric circuits to generate an electric current in the circuits, You should take care of touching the electric lamp in your house on lightening because it is very hot as electric energy is changed into heat and light energies.
You can use the following materials (An electric lamp, An electric bell, a battery, a switch and connecting wires) to set a tool to let a deaf friend have attention, also to set another tool for the same purpose for a friend who can’t see.
It is used as a tool for a deaf person when you connect with the electric lamp with the electric circuit, then close the switch, you observe that the electric lamp lights, It is used as a tool for a blind person when you connect the electric bell with the electric circuit, then close the switch, You observe that the bell rings.
Transformation of energy inside the car
On operating a car engine, several transformations of energy take place in the car, the chemical energy stored in the fuel inside the car engine changes by burning into the thermal (heat) energy that changes into mechanical (kinetic) energy (to move the car), A part of it changes in the dynamo (generator) into electric energy.
Electric energy changes into ( light energy in car lamps, sound energy in the car radio cassette, heat energy in the electric heater of the car air conditioner), So, we deduce the law of conservation of energy: The energy is neither created nor destroyed, but it is converted from one form to another.
Positive effects of technology
Using energy resources for many purposes, Changing energy from one form to another in some applications to be used in man’s life.
Examples of some technological applications:
- Swing machines: Electric energy → Mechanical (Kinetic) energy
- Solar cell: Solar energy (energy produced from the sun) → Electric energy
- Television: Electric energy → Light and sound energies
- Cellular phone: Electric energy → Light and sound energies
- Nuclear reactor: Nuclear energy → Electric energy
Negative effects of technology
Some technological applications have negative effects because some of the technological applications cause environmental pollution such as electromagnetic pollution, noise pollution and chemical pollution of air, water and soil, There are some harms of technological applications when a man uses them in massive destruction, wars & killing.
Examples of some technological applications and their negative effects
- Car exhaust causes chemical pollution of air which causes chest and eye diseases.
- Military explosions leave harmful effects, diseases and cause death.
- Chemical pesticides cause chemical pollution of soil, water & air, they cause cancer & food poisoning.
- Nuclear weapons cause massive destruction.
- The networks of wireless transmitters of cellular phones cause electromagnetic pollution.
- Loudspeakers and drilling machines cause noise pollution.
The car engine is important to the car because in which the chemical energy stored in the fuel is changed by burning into heat energy which changes into mechanical energy causing the operation of the car, Car exhaust is considered from the negative effects of technological applications because it causes chemical pollution of air.
You must rationalize using chemical pesticides because they cause chemical pollution of water, air & soil, and cause cancer and food poisoning, Ecologists do not appreciate all the technological applications which are used in energy transformations because some of these applications have negative effects on the environment.
Properties of Electric current, Simple electric circuit, Current intensity & Potential difference
Potential energy, Kinetic energy & Law of conservation of mechanical energy
Energy resources & forms, Potential energy, Kinetic energy & Mechanical energy
The energy transformation inside the cars
Law of Conservation of mechanical energy in everyday life
