Most of your students know the story of Humpty Dumpty, but they might not know why poor Humpty Dumpty fell. Give students paint supplies and hardboiled eggs and instruct them to paint the eggs to look like Humpty Dumpty. Once the eggs dry, read the Nursery Rhyme to your students and instruct them to drop the Humpty Dumpty eggs when you say "had a great fall." Follow this up with a lesson on gravity.
Another basic example of gravity that kids can identify with is the exaggerated image of an apple hitting Sir Isaac Newton on the head. Begin with an explanation of the basics of gravity. Ask each student to stand up then hand each student an apple or other piece of fruit and instruct them to drop the fruit onto the floor in front of them. Children will be delighted to "make a mess" while being taught a lesson at the same time.
Bring your bathroom scale from home and place it in the front of your classroom. Ask for a volunteer to stand on the scale. Write down the amount the student weighs. Using a science website or computer application, explain to the class how much the student would weigh on each planet. For example, a 70 pound child would weigh only 26.4 pounds on Mercury but 165.4 pounds on Jupiter. Explain how the gravitational pull on each planet is what causes this change in weight.
After a basic lesson on gravity, provide the students with a list of vocabulary words mentioned in the lesson as well as poster board and craft supplies. Instruct them to make a poster that explains the lesson. Get them started with some suggestions such as to draw a cartoon, a diagram or to even make an acrostic using some of the vocabulary you provided.