Rotation revolution 4
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The document discusses rotation, revolution, and their effects. Rotation is an object spinning on its axis, while revolution is an object spinning around another object. The Earth's rotation causes night and day as parts of the Earth face toward and away from the Sun. The Earth's revolution and the changing angle and length of sunlight cause the seasons, with longer days and direct sun rays in summer and shorter days and indirect rays in winter. We can observe the Earth's rotation through star trails, pendulum swings, and ocean and wind currents.
Rotation revolution 4
- 1. Rotation and Revolution What causes night and day? What causes the seasons to change?
- 2. Rotation What does Rotation mean? Rotation occurs when something is spinning around an axis. What are some examples of things that rotate? Tops, Ballerinas, Figure skaters, cyclones, Tornadoes, a merry-go- round, Earth swing.
- 3. Night and Day What causes night and day? The rotation of the Earth • The side of the Earth that is facing the sun has daylight, the side of the Earth away from the sun has night. • It takes 24 hours for the Earth to complete one rotation. • The Earth is tilted on it’s axis at a 23.5 degree angle. • The Earth’s tilt is always in the direction of the North Star.
- 4. • What is another name for the North Star? Polaris This tilt is what causes our days to get longer in the summer and shorter in the winter. Because of the Earth’s rotation the sun appears to rise in the east and set in the west.
- 5. Seasons What two things cause the difference in the seasons? 1. The angle of the sun’s rays 2. The length of the days There are two kinds of rays from the Sun: 1. Direct- occurs when Earth is tilted toward the Sun 2. Indirect-occurs when Earth is tilted away from the Sun In the Summer, we get the direct rays from the sun and the days are longer. (But we are farther away from the Sun) In the Winter, we get indirect rays from the Sun and the days are shorter. (But we are closer to the Sun)
- 6. Summary What is the difference between rotation and revolution? Rotation occurs when an object spins around an axis. Revolution occurs when an object spins around another object. What type of movement causes night and day? The Earth’s rotation What type of movement causes the change of seasons? The Earth’s revolution- the angle of the sun, and the length of the day. How do we know that the Earth Rotates? Star trails, pendulum swings, ocean currents, wind currents
- 7. Summary What is the difference between rotation and revolution? Rotation occurs when an object spins around an axis. Revolution occurs when an object spins around another object. What type of movement causes night and day? The Earth’s rotation What type of movement causes the change of seasons? The Earth’s revolution- the angle of the sun, and the length of the day. How do we know that the Earth Rotates? Star trails, pendulum swings, ocean currents, wind currents