4 Module 59 Science and Health ROTATION OF THE EARTH A DepEd-BEAM Distance Learning Program supported by the Australian Agency for International Development To the Learner The earth is the planet where we are living. It keeps on moving without stopping. This module shows how the earth turns and the effect of its tilt on its axis. Let’s Learn This Describe that the Earth’s axis is tilted 23.5 degrees from the perpendicular. Show that the Earth rotates in a counterclockwise direction as seen from the top of the North Pole. Let’s Try This Read the sentences. Unscramble the letters to know what is described. Write the answers in your notebook. 1. It is the place where people, animals and plants live. THERA 2. An imaginary line which runs through the center of the Earth between the North and South poles. XISA 3. It is the turning of the earth on its axis. TARONOTI 4. The Earth’s axis is . TEDLIT 5. The earth rotates on its axis. What do you mean by the underlined word? PINSS 1 Let’s Study This NORTH POLE AXIS SOUTH POLE The earth is titled on its axis. Look at the illustration. You will notice that Earth tilts on its axis at an angle of 23 ½ degrees. This axis is an imaginary line that runs through Earth. At the two opposite ends of the axis are the North Pole and the South Pole. The tilt of Earth’s axis makes day and might unequal in length. The globe represents the Earth. It spins or rotates on its axis. Earth’s axis is not perpendicular to the plane of its orbit. It rotates from west to east and appears to rotate counterclockwise viewed from the North Pole. It takes about 24 hours or one day for Earth to make a complete rotation. There are about 12 hours of daytime and 12 hours of nighttime which make one whole day. Procedure: 1. Get a globe and locate the Philippines by marking with a colored chalk. 2. Position the globe so that its axis points toward you. 3. Slowly spin the globe counterclockwise until it reaches the position from where it started. 4. Describe the movement of the globe. 2 When you spin the globe until it reaches point from where it started, this movement is called ROTATION. To rotate mean to spin. Let’s Do This A. Study the pictures below. N S Compare the movement of the hands of the clock and the rotation of the Earth. Questions: 1. In what ways are they similar? 2. In what ways are they different? B. Supply the correct answer. . 1. The Earth tilts on its axis at an angle of 2. An imaginary line that runs through the earth . 3. The two opposite ends of the axis are and . 4. One complete rotation of the Earth is hours or day. 5. Earth rotates on its axis from 3 to . Let’s Remember This The globe is a model of the earth. It spins and turns around. The earth moves similarly as the globe does. It rotates on its axis continuously. It takes the earth 24 hours (one day) to spin around once on its axis. The earth rotates in counter –clockwise direction. It rotates from west to east. This makes the sun seems to rise in the east and travel across the sky then sets in the west. Let’s Do More A. 1. In what direction does the Earth rotate? a. from east to west c. from south to north b. from north to south d. from west to east 2. How long does it take for the Earth to make a complete rotation on its axis? a. one day b. one month c. one week d. one year 3. At what angle does the Earth tilt on its axis? a. 43 ½ degrees c. 33 ½ degrees b. 23 ½ degrees d. 53 ½ degrees 4. What do you call an imaginary line than runs through the Earth? a. axis b. taxis c. orbit d. faxis 5. The movement of the globe as it spins and reaches the point ? from where it started is called a. revolution c. rotation b. locomotion d. position 4 Let’s Test Ourselves A. Identify the following. 1. The turning of the earth on its axis. 2. The trip of the earth around the sun. 3. The number of hours it takes the earth to make one complete turn on its own axis. 4. Angle of earth’s tilt on its axis. 5. It makes day and night unequal in length. 6. The earth’s movement which causes day and night. 7. The direction of the earth’s rotation. 8. The imaginary line connecting the North and South Poles. 9. The imaginary path the earth follows as it revolves around the sun. 10. The direction of the earth’s rotation as seen above the North Pole. Science Fact File The direction of the Earth’s rotation means that the Sun appears to rise in the East and set in the west. If you imagine that you are standing at the North Pole and looking down on the earth, it would rotate anticlockwise. In other words, the Earth rotates towards the East, so the Sun first becomes visible from that direction. Source: Encyclopedia of Question and Answer 5 Answer Key Let’s Try This 1. Earth 2. Axis 3. Rotation 4. Tilted 5. Spins Let’s Do This A. 1. They rotates 2. The earth rotates counter-clockwise B. 1. 23 ½ degrees 2. axis 3. north pole and south pole 4. 24 hours or 1 day 5. west to east Let’s Do More A. 1. d 2. a 3. b 4. a 5. c Let’s Test Ourselves A. 1. rotation 6. rotation 2. revolution 7. west to east 3. 24 hours 8. axis 4. 23 ½ 9. orbit 5. earth’s tilt 10. counter-clockwise 6