Teacher Name: Gemma Griffin
Grade Level: 4-6
Subject: Science
Time Frame: 1 hour 30 minutes
Concept: Forces and Movement
Topic: Gravity
Rationale:
Gravity is a difficult and very abstract, but important concept for students to understand, as well as to teach. Gravity and the center of gravity is what keeps us from floating away, falling over, being able to ride a bike; and it affects many other countless activities in our daily lives. It is important for students to have many hands-on and engaging experiences with gravity first hand so that students come away with a more in-depth and self-constructed meaning of gravity.
Goals: The student will become familiar with the force of gravity.
The student will be engaged in manipulating the center of gravity.
The student will understand how gravity affects their lives.
SOL: Science:
4.1 The student will plan and conduct investigations:
– in which predictions and conclusions (inferences) are made.
5.1 The student will plan and conduct investigations:
– in which estimations of length and mass are made.
6.10 The student will investigate and understand:
– the role of gravity
Objectives:
Cognitive:
The student will be able to investigate the effects of gravity during a set of hands-on experiments, evidenced by completion of oral discussion, the experiments, and a written journal. See attached rubric.
Affective:
The student will be able to develop an awareness of how gravity affects our every day activities and lives through a set of experiments, oral discussion, and completion of a written journal. See attached rubric
Psychomotor:
The student will be able to manipulate both gravity and the center of gravity to create an object that balances, evidenced by successful completion of the experiment and science journal. See attached rubric.
Materials:
Science Journals
Blank paper
crayons/markers
ball
glass w/water
book
lots of newspaper
plastic cups (3 per group)
water
food coloring
straws or eyedroppers(3 per group) *TIP: if you use straws, let students practice picking up and dropping water with it.
craft paper
Splish-Splash Paintings journal (Science Art p. 131)
scissors
3 yardsticks
masking tape
3 heavy books
Balancing Clown pattern page (Science Art p. 132)
thin cardboard or cardstock paper
glue
paperclips
pencils
Advanced Organizer: 20 minutes
Draw a Scientist (10-15 minutes) Give students materials to draw a scientist how they think a scientist should look. To be scored later to identify stereotypes and conceptions about scientists that students hold.
Explain to students that they are going to be scientists today.
1. Select students to do the following: (5 minutes)
a. toss a ball up in the air.
b. slide a book off the edge of a desk.
c. jump up.
d. pour a small amount of water from a glass.
Ask students what similar thing occurred in each event. (Everything eventually moved downward).
Procedures & Activities:
I. Intro to Gravity (5 minutes)
1. Ask students what holds us on Earth and keeps us from toppling over when we walk? What made the previous activities (dropping a ball, jumping up) result in moving downward? Allow students think time before having them share their ideas.
2. Explain to students that gravity is the invisible force that pulls all objects downward, and pulls things, including people, towards Earth. (A force is anything that pushes or pulls on an object. A push or pull can change an object’s speed or direction of motion.)
II. Splish-Splash Paintings (25 minutes)
1. Students will be exploring how gravity affects falling objects.
2. Divide students into small groups of 3 or 4 using colored paper. Have each group set up a work area by spreading newspaper on the floor. Prepare three paint cups for each group by mixing water with different food colorings. Put an eyedropper or straw into each cup.
3. Place a sheet of craft paper on the newspaper for each student in a group. Give everyone a journal page.
4. Ask students to test the effect of dropping paint from different heights.
a. Predict and draw on the journal chart the size splash the drop will make if you hold the dropper at shoulder height. Release a drop. Observe the splash size. Label this splash “shoulder height”.
b. Repeat step A a second time at waist height, and a third time at knee height.
c. Each time use a different color of paint and hold the dropper over a different place on the paper. Let a drop fall from each height, observe the splash size, and label the craft paper.
5. When the splashes dry, have student cut them out and paste them on their journal charts then compare, in writing, the predictions with results.
*Scheduled 15 min snack/break while waiting for paper to dry. It won’t take more than 5 minutes.
When student come back from break and have completed their journals ask:
Did your predictions get more accurate each time you tried a new drop? Do drops that fall from higher up make splashes that are bigger or smaller? Why?
III. Balancing Clowns: Gravity Extension (30-35 minutes)
1. Ask: Since gravity pulls everything downward, why don’t we fall down? Allow wait time before having students share ideas.
2. Our muscles help us stand up straight against gravity’s force. And the floor pushes upward to stop our fall. In addition, all objects have a balancing point of center of gravity.
3. Help students explore the concept of balance with their own bodies. Tape the yardsticks to the floor, end to end. Invite students to take turns walking the length of the yardsticks, holding their arms out from the sides, without letting their feet touch the floor.
4. Then have students try walking the length of the yardsticks:
a. arms crossed over chest.
b. holding a heaving book in one hand, with the harm held out to one side.
c. holding the book with both hands, below your waist, close to your body.
5. Discuss results. Which method was easiest? Hardest? (holding out arms is easiest because it redistributes weight. Crossed arms is harder to balance, and holding the book in one hand throws the body off-balance because the center of gravity moves to one side. But by holding the book close to the body lowers the center of gravity and keeps it over the feet, also making it easier to balance.)
6. Hand out the Balancing Clown pattern. Have students glue the page to cardstock, then cut out their clowns.
7. Challenge students to balance their clowns by the head on their fingertip or on the end of a pencil. Can they do it? (probably not).
8. Explain to students that by adding weight somewhere on the clowns, students can make them balance. Ask students to predict where they should place paper clips, and have them sketch ideas in their science journal.
9. Have student experiment with paper clips on their clowns to test their predictions until they find a way to balance the clown.
10. Have students draw pictures in their science journals showing how they made their clowns balance.
Closure: (5 min)
Discuss as a class the best place to add weight to the clowns. (2 or more paper clips on each hand to evenly distribute the weight and to offset the force pulling down on the clowns body and legs.) End by discussing and having students write/illustrate in their journals ways balance and gravity affects us in everyday life (riding bikes and skateboards for example).
Assessment/Evaluation:
See attached rubric for worksheet.