Tides

Different ways the sea meets the land.ppt

1. Have the class form a circle in a large area. This could be in the classroom, gymnasium, on a lawn, or on the playground.

2. The ideal way for students to sit is crossed-legged with hands holding the next person's elbows to form a strong circle. If the class is reluctant to touch, have them kneel "knock-kneed" next to each other in a circle.

3. One person is the moon and moves around the outside of the circle. The circle is the waters of the earth. As the moon passes behind the students (water), the waters bulge (lean) toward the moon, and then into the center as the moon passes. As the moon moves, have the students that are opposite the moon lean away from the moon (this represents water bulging out on the opposite side of the earth) and then have them lean into the center as the moon passes.

4. Have the moon stop, and let the class see where the high tides are (next to the moon and at the opposite side of the circle). Then the moon continues to circle. Have the moon stop at several points in the circle and let the class see where the high and low tides are in relation to the orbit of the moon. (Low tide will be at the sides halfway between the high tide bulges.)

5. The moon can then circle the earth several times so the rhythm of the passing of the moon and the bulging of the waters is experienced by the class. Before ten minutes are up, even first and second graders have a feel for how the moon affects the tides.