الصف الرابع الابتدائي ساينس
ساينس رابعة ابتدائي

لينك تحميل الملزمة
https://drive.google.com/file/d/19H2SesOszQ8LkyxBlF-9xXxLoRRd16Tz/view?usp=sharing

لينك تليجرام
https://t.me/scimrahmedelbasha

In This Video :
The Sun
•The Sun is a star and like all stars, it is made up of gases (mostly hydrogen and helium gases).

• The Sun does not have a hard surface like the moon, but it has a surface known as the "photosphere".

• The photosphere is the gas layer at the surface of the Sun, where the light we see is emitted.

How does the Sun produce light and heat ?
- The energy of the Sun comes when hydrogen and helium gases in the Sun react
at very high temperatures, producing huge amounts of light and heat.
- Light and heat travel through space in the form of waves, some of these waves
reach the Earth.

Solar energy
•The energy comes from the Sun is called "solar energy", which is radiant light and heat from the Sun.
•The solar energy that is produced by the Sun contains a type of energy called
"radiant energy" (radiation) which is found in the Sun rays.

Uses of solar energy
Direct source of thermal energy
Solar energy can be used directly as a source of thermal
energy when exposing yourself to the Sun to feel warm.

In greenhouses
Where, greenhouses allow the entry of solar energy
(especially radiant energy) that comes from the Sun, then this radiant energy is converted into thermal energy that warms the inside of the greenhouses, which helps farmers
to plant the crops that only grow in warm climates.

In warming houses
Where, houses can be built in a way that enables the energy of the Sun to warm them by placing large windows on the walls that face the Sun for most of the day.

In cooking food
Where, curved mirrors are used to collect and focus Sun
rays to heat metal pots and cook the food inside.

In heating water
Where, panels made of black pipes can be placed on the roof of houses to heat the water when it passes through these pipes, then the heated water is stored in a water tank to be used later.

Solar panels
Solar panels can be very small that they can supply only one light bulb with energy, or very large that they can supply buildings or cities with energy.

How do solar panels work?
• Solar panels are composed of many small solar cells.
• These cells capture solar energy (especially radiant energy) coming from the Sun
and convert it directly into electrical energy or thermal energy.
• Most solar panels are used to generate electricity.

Uses of electricity generated by solar panels
• This electricity can be used directly to light the streets.
• This electricity is used to recharge some types of batteries, like some calculators with small solar cells.
•This electricity is used in houses to operate various electric devices.
• This electricity is used to operate irrigation equipment in some villages .


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