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Ahmed saied Thu 11 Nov 2010, 4:49 amEnergy Transformations:
- Energy can change from one form into another.
- An object save its mechanical energy which alternates between potential energy and kinetic energy and this is known as "the conservation law of mechanical energy".
The conservation law of mechanical energy:
The sun of potential and kinetic energies of an object under the effect of gravity is a constant value.
The conservation law energy:
Energy is neither created not destroyed, but it is converted from one form to another.
- When two different metals (zinc and copper) are dipped in an acidic solution (lemon juice), chemical energy changes into electric energy.
- The simple electric cell consists of an acidic solution dipped in it two different metals, so in the simple electric cell, chemical reactions convert chemical energy into electric energy.
- If a potato is used instead of the lemon (acidic solution) the electric current from the simple cell will be produced because potato has a salt solution to complete the reaction.
- In the electric lamp, the electric energy changes into light and heat energies.
Technological applications and changes of energy:
- A sewing machine converts electric energy into mechanical (kinetic energy).
- A torch converts chemical energy (stored in the battery) into light energy.
- A television converts electric energy into light and sound energies.
- An alarm clock converts chemical energy (stored in the battery into kinetic energy) (the movement of the hands) and sound energy.
- Washing machine converts electric energy into kinetic energy.
- Mobile phone converts electromagnetic energy into sound energy.
Energy and environment:
There are lots of damages due to some of the technological applications of energy changes such as:
1- Transportation means cause air pollution which causes chest and eye diseases.
2- Military weapons cause war and death.
3- Chemical pesticides damages and pollutes plants also cause chemical pollution of water, air and soil which causes cancer.
4- Nuclear weapons cause massive destruction and leave harmful effects behind them for a long time.
5- Mobile phones in which the networks cause harmful effects on people suffering from heart diseases (electromagnetic pollution
- Energy can change from one form into another.
- An object save its mechanical energy which alternates between potential energy and kinetic energy and this is known as "the conservation law of mechanical energy".
The conservation law of mechanical energy:
The sun of potential and kinetic energies of an object under the effect of gravity is a constant value.
The conservation law energy:
Energy is neither created not destroyed, but it is converted from one form to another.
- When two different metals (zinc and copper) are dipped in an acidic solution (lemon juice), chemical energy changes into electric energy.
- The simple electric cell consists of an acidic solution dipped in it two different metals, so in the simple electric cell, chemical reactions convert chemical energy into electric energy.
- If a potato is used instead of the lemon (acidic solution) the electric current from the simple cell will be produced because potato has a salt solution to complete the reaction.
- In the electric lamp, the electric energy changes into light and heat energies.
Technological applications and changes of energy:
- A sewing machine converts electric energy into mechanical (kinetic energy).
- A torch converts chemical energy (stored in the battery) into light energy.
- A television converts electric energy into light and sound energies.
- An alarm clock converts chemical energy (stored in the battery into kinetic energy) (the movement of the hands) and sound energy.
- Washing machine converts electric energy into kinetic energy.
- Mobile phone converts electromagnetic energy into sound energy.
Energy and environment:
There are lots of damages due to some of the technological applications of energy changes such as:
1- Transportation means cause air pollution which causes chest and eye diseases.
2- Military weapons cause war and death.
3- Chemical pesticides damages and pollutes plants also cause chemical pollution of water, air and soil which causes cancer.
4- Nuclear weapons cause massive destruction and leave harmful effects behind them for a long time.
5- Mobile phones in which the networks cause harmful effects on people suffering from heart diseases (electromagnetic pollution
