شرح ساينس الصف السادس الابتدائي لغات - الفصل الدراسي الأول
شرح ساينس سادسة ابتدائي - ترم أول

لينك تحميل الملزمة
https://drive.google.com/file/d/1Pb-v4Y-ivNhUz-JGG59l1Ak4V0ioaT0s/view?usp=sharing

لينك تليجرام
https://t.me/mrahmedelbashagroup

In This Lesson:
Conduction:
Heat transfers by conduction when objects with different temperatures touch each other.
Example:
When you have a fever and your temperature is high, you put cooling pads to transfer the heat from your body to the cooling pads by direct contact.


Convection:
Heat transfers by convection due to the movement of a liquid or gas.
Example:
► When we cook noodles, we put noodles and water in a pot.
► During heating, the noodles close to the bottom of the pot that is near the heat source get hot and rise to the surface, then cold noodles at the surface moves down to the bottom of the pot and so on.
► The movement of noodles up and down shows the movement of water in the pot during heating, where:
- Hot water at the bottom of the pot moves up.
- Cold water at the surface of the pot moves down.
- The continuous movement of water up and down causes the transfer of heat through water by away known as convection.

Radiation:
Heat transfers by radiation through gases and space.
Example:
- When your hand gets close to a fire, you feel warm because the air between the fire and your hand allows the thermal energy of the fire to transfer to your hand.


- In sunny days, we feel the heat of the Sun although there is a space between the Sun and Earth.
- Space where the thermal energy of the Sun transfers to Earth through the space by away known as radiation.



 
The speed of transfer of heat:


Materials are classified according to the rate of transferring heat into:
Thermal conductors Thermal insulators
They are materials that allow
thermal energy to transfer through.
Or
They are materials that allow heat to travel freely through them. They
are materials that resist the transfer of thermal energy
Or
They are materials that slow down the heat transfer.
Examples:
Metals such as copper, iron and
aluminum. Examples:
Air, plastic, wood and glass.


Examples:
1. If you pour hot water into a metal bowl and a plastic bowl, you will notice that:
- The metal bowl is hot


- The plastic bowl is just warm
Because:
- Metal is a thermal conductor, so it allows thermal energy to transfer through.
- Plastic is a thermal insulator, so it slows down the transfer of thermal energy.




بالتوفيق
مستر احمد الباشا