why do we have night and day
The styrofoam ball represents the Earth. Draw the outlines of the continents on the styrofoam using a pencil. You will use the globe model (shown by your teacher) or the map of the globe on the projector as drawing guides. The drawing does not need to be detailed. Just make sure to draw the Philippines clearly. Include also Brazil which is on the opposite side of the Philippines. Color the drawn continents (land) green and the ocean (water) blue using the highlighters. Students must cooperate in drawing and coloring their own БEarth. Б
Carefully pierce the barbecue stick through the middle of the styrofoam ball. Use the marks as guide. The barbecue stick represents the line about which the Earth spins or rotates.
This represents the Earth's axis of rotation. Take the two pieces of straws. Insert them over each end of the axis piercing the styrofoam ball. Make sure that they cover the barbecue stick entirely. Take the illustration board and investigate. The number written on it (degrees, symbolized as O) is a measure of the tilt of the Earth. Remember that the EarthБs axial tilt is 23. 5O degrees. Stick the two ends of the straw along this axis using the tape. Fold the flap to make the stand. The Earth should turn freely when you try to rotate it. You are almost done. Put the Philippine flag in place and also the Brazil flag opposite it. The flags represent the two БextremeБ positions on Earth.
Make the room completely dark. Using the flash light (representing the БSunБ), shine sunlight onto the Earth. The flashlight should not move. When light strikes the Philippine flag (day), take note that no light falls on Brazil (night). The Philippines is at Бnoon,Б the light shines directly on it. Then turn the globe eastward (from left to right) slowly until their positions reverse. Brazil now experiences daylight while Philippines experiences nighttime. As the БEarthБ moves, this pattern continues. Why do we have night and day? We are able to separate between night and day because during the day we have sunlight and during the night there is no sunlight.
The reason for this is that the Earth is constantly turning on its axis which is an imaginary line that passes between the North and South Poles. Light from the Sun will only shine on the half of the Earth that is facing the Sun. On the other half of the Earth there will be darkness because no sunlight can reach the other side. It takes the Earth 24 hours to complete a full spin on its axis and that is why a day lasts for 24 hours. Similarly, if only one half of the Earth sees the Sun at a time, that is why daylight is 12 hours and a night-time is 12 hours. Why does the Sun seem to move across the sky? It is not the Sun that is moving across the sky, it only looks like the Sun is moving because the Earth is spinning on its axis.
It looks like the Sun is moving across the sky from east to west but it is in fact the Earth spinning on its axis from west to east. This is why the Sun rises in the east and sets in the west. When it is night-time and we can no longer see the Sun the same effect happens with stars в it looks like the stars are moving from east to west in the sky, but this is just the Earth spinning on its axis. What causes a sunrise and sunset? A sunrise and sunset is caused when the Earth in your particular location has beginning to face the Sun (sunrise) or starting to face away from the Su (sunset). The time for sunrises and sunsets will be different depending on where you are located on the Earth.
Why do some countries receive more daylight than others? The Earthвs axis tilts slightly (23. 5 degrees) and because there is a slight tilt we have seasons. If one hemisphere points towards the Sun it will receive more light from the Sun and it will be a season such as summer because it will be light and warm, whilst at the same time the other hemisphere will be away from the Sun so it will be dark and colder. The effect is lesser at the equator because areas on the equator receive about the same amounts of Sun each year. At the poles however, during the winter months they will receive virtually no sunlight at all which is why they stay frozen.
- Autor: Roto2
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