Science - 3rd Grade
Standard 4 Objective 2
1 class periods of 45 minutes each
Gravity has different effects on the motion of an object rolling up or down a hill. The incline of the hill makes a difference in speed and distance.
For each group (2-4) of students:
These investigations are enjoyable for students to try when learning about the effects of gravity on the motion of an object. This activity not only investigates a science principle, but requires the group to cooperate and communicate effectively to experience success. Working together will help students solve problems while learning about gravity.
Students should understand that gravity is a force and that objects are pulled toward the Earth by gravity. They will find a working vocabulary of force and motion helpful in explaining the results of their experiments.
1. Conduct a simple investigation.
2. Explain science concepts and principles.
Step 1. Divide students into small groups and pass out one marble to each group, and a tube to each student.
Step 2. Tell students that each group has the responsibility to work together and, using the tubes and every person in the group, get the marble from one wall of the room to the opposite wall. Remind the students that they will need to discuss their strategies to accomplish this objective. If, during their attempt to move from one wall to the other, the marble falls to the ground, (remember, gravity is very powerful!) they will need to start over. The first team to reach their goal needs to stand in a line and yell "gravity" together.
Step 3. Have students sit with their group as you discuss what occurred.
Step 5. Have each group fold a piece of paper into eight squares, four horizontal boxes by two vertical boxes. Label each box across the top with one of the following:
Step 6. Each group will conduct experiments and record how far their marble rolls at each incline in the boxes on their page. They will need to set some criteria about the amount of force applied (push) to get the marble going, especially when they are rolling uphill. Remind them to keep the forces the same so their results are valid.
Step 7. At the end of the experiments, have each group share their results. You might want to post their charts to allow the class to view everyone's data.
Ask students questions about the activity:
Students could design a rolling machine (not necessarily a car) that would compete in races. Limit the materials that can be used to such as erasers, index cards, paper clips, etc.
Ask students to fold a paper in half and then draw a picture of a person participating in some activity that requires them to go up or down an incline. (Up on one side, and down on the other.) Have them write one or two sentences that describe the effect of gravity on their activity. ("Hiking uphill makes me hot and tired." "Hiking downhill is fun because you almost run. Watch out or you might roll all the way down!")
Review data charts for experiments to see if students have grasped the principle of gravity making things easy or difficult.
Collect science journals and look for accurate observations and statements.