Energy from the Sun

Energy from the Sun

     Energy from the Sun travels through Earth's atmosphere. When some of that energy is absorbed by yoir skin, it is cjanged into heat.

     This is an example of the transfer of energy by radiation. Radiation travels in the form of waves. Because the Sun's radiation consists of waveshaped electric and magnetic fields, it is called electromagnetic radiation. 

     Some of the Sun's radiation is in the form of visible light. Other radiation has slightly higher frequency, and is called ultraviolet (UV) light. Radiation of slightly lower frequency is called ifrared (IR) light. UV and IR light are invisible to humams, but you still feel their effects. IR light warms you. Too much UV radiation from the Sun can cause a sunburn, which is why you should ise sunscreen! 

     Earth recieves only a tiny a,ount of the electromagnetic radiation the Sun gives off. However, this radiation is enough to power Earths water cucle, creat weather, and provide the energy that plants need to grow.
     The following link shows an illustration of what happens to the energy that reaches Earth.

100% of tje Sin's energy that reaches the Earth

     Earth's surface is warmer during the day and colder at night. The atmosphere keeps these temperatures in a moderate range. Considere the Moon. With barely any atmosphere to absorb or radiate heat, ots temperatire changes enormously every day. Daytime on the Moon is very hot, and nighttime very cold. 

     Earth's atmosphere is heated by Earth's warm surface, not directly by the Sun. Much of this energy is transferred by convection, which is the transfer of heat by circulation in gas or liquid. 

     Air rises or skins because of its density. Warm air os less dense tjan cold air, so it rises. Cold air is denser than warm air, so it sinks. As shown on the illustrarion of the following link, this can create a loop of moving air, called a convection current. 

Sea breeze; Land breeze


     Warm and cold air also create differences in air pressure. Rising warm air lowers tje air pressure below it. Sinking cold aor incrwases the air pressure. As in land and sea breezes, air moves from areas of high pressure to areas pf low pressure. Winds always blow this way. 
     Convection cirrents and differences in air pressure are caused by the Sun heating Earth's surface unevenly. Tje areas near tje equator recieve tje most energy from the Sun. The poles recieve the least. 
     The uneven heating results in low air pressire at the equator and high aor pressire at the poles. Therefore, air tends to move from the poles toward equator. 

Recycling

Recycling video

Unit: Cells to body; Lesson: What are cells?

Unit: Cells to body; Lesson: What are cells?

     Lets review the parts of a cell. Click the following links to watched the videos: 

Cell stucture and function

Parts of the cell - country

Parts of a cell - rap

Web page

For next semester, we are going to use the following web page. I invite you to start visiting it, to get familiar with it and to learn how to use it. It is going to be our classes web page, and we are going to be working with it and at it. Is not finished yet, but you can get familiar with it. 

Web page: gladimardejesus.com

Unit 2: The Engineering Process; Lesson 3: How does technology improve our lives?