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Grade Level: 5th-6th grade

Time: 60 minutes

Lesson Objective: Students will observe the principles of gravity and extend their understanding of the concept through experimentation.

Background Information: Students will come into class and find "If I dropped a baseball and a marble, which one would hit the ground first and why?" written on the board.

Materials Needed:

• Feather
• Baseball
• Ping Pong Ball
• Paper
• Marble
• Timer (optional)

Teaching Strategy: Most of the learning in this activity will be in group discovery learning. The students are allowed to split into groups of 2-4 people. The teacher serves as a guide and the students are encouraged to lead the discussion.

Procedure: 1) Ask students to voice their thoughts on the question. Do not tell them if they are right or wrong, but demonstrate and let them decide how right or wrong they are. Stand on a chair and tell them that you are all going to find out which will hit the ground first, the baseball or the marble. Holding the objects about shoulder high, drop them. Ask students if one hit the ground before the other or if they hit the ground at the same time. After hearing several answers, repeat the experiment so that they can see that they both hit the ground at the same time.

2) Pass the objects around and ask the students, "that was kind of odd don't you think? I mean the baseball is heavier than the marble isn't it?" Students will confirm that this is the case. Pretend to ponder this and say, "I think we need to experiment and see if this happens with the other objects."

3) Hand out the data collection sheet and read the directions aloud as they read silently. Allow them approximately 10 minutes to experiment.

4) After the experiment is over, have students report if their predictions were correct or otherwise. Ask them to look at their experiment and see if they could identify why some objects hit the ground before others. Example, the unfolded sheet of paper will hit the ground much later than the ping pong ball, but once the sheet of paper is crumpled into a ball, they both hit the ground at the same time. Ask why this might happen. Steer the discussion in the direction that while weight may not affect the rate at which objects fall, shape certainly does. Ask students to explain why this might occur.

5) Ask "does gravity change?" Answer them carefully, but explain that gravity remains constant. Ask, "when the wind is blowing really hard, what's the easiest way to walk into the wind? Do you bundle up (demonstrate wrapping yourself up and hunching down as you move forward) or do you spread your arms wide and try to walk into the wind? Which will make it easier for me to move?" Take answers. They will mention that if you huddle up and hunch over that it will be easier to walk than with your arms spread out. Ask them to explain and you will get answers such as; when you spread your arms ourt, the wind hits more of you-like a kite and makes it harder to walk. Agree...explaining that it creates more surface area creating greater resistance. Hold up a crumpled piece of paper and an unfolded sheet and ask, "pretend that this piece of paper is a person. Which of these will make it to the ground more easily?" The crumpled one because less air is hitting it.

6) "Why is it important to know about gravity?" Take answers and write them on the board. Explain that gravity helps us move, float, fly, and grow plants. Explain that understanding how much gravity has will determine how we work, travel, and grow plants.

Conclusion: Conclude the lesson by assigning a journal - "How does gravity affect my everyday life? How would it be different if there was no gravity?"

Objective Restated: After observing the principles of gravity through experimentation, the students have extended their knowledge and understanding about the processes of gravity.

Evaluation: Walk through the classroom observing and answering questions. Assess the accuracy of their work and following of directions, ability to think critically, and contribution to the group. Also take up the journal for a participation grade. Check out the Links page to find great sites to enhance this class activity!