Does the earth spin clockwise full#

Question 3: The concepts of вЂњupвЂќ and вЂњdownвЂќ are determined by the action of gravity on a planetвЂ™s surface.Question 2: Up and down are determined locally: Up is away from the center of the Earth and down is toward it.In other words, the flow of rivers depends only on local topography, not on cardinal directions (north/south/east/west). Question 1: Students should realize that rivers flow downhill, which means their direction of flow is determined by changes in altitude.Here are some discussion points to consider.

Does the earth spin clockwise full#

You may need to guide the students in their small group discussions as well as in the full class discussion that follows. As weвЂ™ll discuss in Chapter 2, the fact that EarthвЂ™s axis is tilted explains why we have seasons.ДЇigure 1.28 вЂ“ This diagram shows key features of EarthвЂ™s orbit around the Sun. This tilt happens to keep EarthвЂ™s axis pointed in the direction of a star called Polaris, or the North Star. EarthвЂ™s axis is not straight up and down compared to the ecliptic plane rather, it is tilted by 23ВЅВ°.EarthвЂ™s orbital path defines a flat plane, called the ecliptic plane.Figure 1.28 shows a diagram of the orbit. You already know that the distance from Earth to the Sun is called one astronomical unit (AU), which is about 150 million kilometers. WeвЂ™ll therefore think of it as being nearly a circle with the Sun at the center. The orbit is not quite a perfect circle (rather, it is a oval-like shape called an ellipse), but it is close. OrbitД®arth also orbits the Sun, completing one orbit each year. Step 3 Explain: A person at the equator is moving with EarthвЂ™s rotation at a speed of about 1,670 kilometers per hour, which is a little over 1,000 miles per hour, or about twice the flying speed of a commercial jet. Step 2 Solve: We divide the distance by the time of 24 hours: The time is 24 hours, because that is how long each rotation takes. In this case, the distance is the distance that a person at the equator travels with each rotation, which is EarthвЂ™s equatorial circumference if you look it up, youвЂ™ll find that this is 40,074 kilometers. If you remember that highway speeds are posted in miles (or kilometers) per hour, youвЂ™ll realize that speed is a distance (such as miles) divided by a time (such as hours). Step 1 Understand: The question how fast tells us we are looking for a speed. Together, the strength of Earth's gravity and the long rotation period counteract any feeling of being вЂњflung offвЂќ that we might otherwise have, explaining why we donвЂ™t feel EarthвЂ™s motion. The downward force with which EarthвЂ™s gravity holds us to the ground is much stronger than the outward force we feel from being вЂњflung offвЂќ with EarthвЂ™s rotation (more technically called a centrifugal force). ThatвЂ™s much longer than it takes a merry-go-round to rotate, and this means that any feeling of being вЂњflung offвЂќ is much weaker for Earth than for the merry-go-round. Even though EarthвЂ™s rotation is carrying us around the axis at a fairly high speed, it still takes a full day to complete one rotation. The answer comes from a combination of two main factors. After all, if you ride on a fast-moving merry-go-round, youвЂ™ll feel yourself being вЂњflung offвЂќ unless you hold on tightly. Given those high speeds, you might wonder why we donвЂ™t feel ourselves moving on the rotating Earth. The only object that can appear to move differently are human-made satellites in low-Earth orbit, which can appear to move through the sky in other directions because there are orbiting Earth faster than Earth is rotating. For the discussion in step 4: The correct answer is that all these objects appear to rise in the east and set in the west for the same reason our Sun does - their apparent sky motion is a simple consequence of EarthвЂ™s rotation.Fyi, the reason we suggest the darkened room is so that the video will show only see the bright lamp in a brighter room, the presence of other objects will distract from the point that the lamp seems to move when you watch the video, even though it was you (or the student) rotating as you made the video. This works well with smart phone cameras set to video, and if your students have smart phones, they can all do the same activity so each student sees it for him/herself.This is analogous to why EarthвЂ™s daily rotation caused the Sun to appear to rise and set in our sky. This activity is designed to show students that if they record a video while rotating, the object(s) they are recording will seem to be moving when they replay the video.