To identify ways to make objects move; to construct a structure that can be used to move an object from one place to another.
Finding answers to questions means using one's hands and senses as well as one's head. Students should have opportunities to use tools, along with scientific and mathematical ideas, to solve problems and figure out more about how the world works. (Benchmarks for Science Literacy, p. 292.)
In this lesson, students study the motion of objects in order to create a structure that can be used to move an object from one place to another. They are encouraged to observe and test their structures, revising them as needed.
As part of this lesson, students will make many discoveries about how and why objects move. They will explore and manipulate the motion of objects and the forces required to control that motion (pushing, pulling, throwing, dropping, rolling, and so on). This will help them understand that the position and motion of objects can be changed by pushing or pulling and that the size of the change is related to the strength of the push or pull. This is important because research suggests that students tend to think of force as a property of an object ("an object has force," or "force is within an object") rather than as a relation between objects. (Benchmarks for Science Literacy, p. 339.)
In addition, students tend to distinguish between active objects and objects that support or block or otherwise act passively. Students tend to call the active actions "force" but do not consider passive actions as "forces." Teaching students to integrate the concept of passive support into the broader concept of force is a challenging task even at the high-school level. (Benchmarks for Science Literacy, p. 339.) Therefore, students should have many additional opportunities to view, describe, and discuss the movement of objects and to identify the forces behind them.
Begin this lesson with a fun activity that will motivate and engage your students. In this activity, students should find all of the different ways to move a ping-pong ball from one location to another. (Other rolling objects, such as superballs or small toy cars would be equally suitable.)
Pose this question: "How many different ways can you make the object go from one place to another?" Have students work in pairs or small groups to explore all of the possible ways to make the objects move. If possible, have a variety of materials available for this investigation, such as: flat pieces of cardboard or wood, books, string, straws, etc.
Allow students to share and discuss how they were able to get the object to move. Encourage students to record their observations and results on the Making It Move student sheet. Create a class list of techniques for moving objects: pushing, pulling, kicking, throwing, sliding, rolling, dropping, blowing, etc.
In each case, have students consider these questions:
- What is the effect on the motion of the object?
- Does the object move faster? Slower?
- What is the direction of the motion? Does the object move in a straight line? Zigzag? Round and round? Back and forth?
- Does it change direction?
Encourage your students to return to the "drawing board" and keep experimenting. Then ask students:
- Which of the methods you used required the use of other materials?
- Compare other solutions used. Which methods made the object go fast? Required the object to leave the floor? Made the object go zigzag?
- How did you get the object to move?
- Can you think of another object that could be moved in the same way? What makes you think so? How is the object you're thinking of like the one you've already moved?
- Can you think of an object that could not be moved in the same way? Why not? How could you move that object?
Discuss the movement of rolling objects, asking students:
- What kinds of objects can roll? What do these objects have in common?
- How can you start an object rolling?
- How can you stop an object from rolling?
- Can you think of a way to make something roll in an exact path? (build a track) What other things move on a track?
Tell students that they will try to build their own track for the ping-pong ball, marble, or toy car using cardboard tubes and masking tape. Continue to have students work in pairs or small groups. Give each group a ping-pong ball, marble, or toy car and a selection of cardboard tubes. Ask students, "How could you make the objects move using the cardboard tubes and masking tape?" "Where do you think the object will go?" Write down students' answers on a large sheet of paper or a blackboard at the front of the room. Now have students test their ideas. Students will create a track that will be used to stop the ball as close to an exact position as possible. Provide students with a measurable distance for which to aim, so that they can test and adjust their structures as needed. Again, encourage students to record their observations and results on the Making It Move student sheet.
Ask students to consider these questions:
- How can you build the track to slow the ball down?
- Speed it up?
- Make it go further?
- Make it go a shorter distance?
- Turn a corner?
Consider posing other challenges, such as:
- Build the fastest track possible.
- Build the slowest track possible.
- Build a track that will allow the ball or car to dip down to a lower point and then go to a slightly higher point.
Ask students to complete this assignment:
- Draw a picture of the structure you built. Explain what it does and how it works, using words and/or pictures.
- Draw a picture to show what you could do to the structure to make the ball (or car) go faster.
- Draw a picture to show what you could do to the structure to make the ball (or car) go slower.
To extend the ideas in this lesson, you can lead students through two other Science NetLinks' lessons that focus on manipulation and observation.
- Ramps 1: Let It Roll! allows students to explore and measure the rate of spherical objects rolling down a ramp.
- Ramps 2: Ramp Builder encourages students to plan, build, and test a ramp that allows objects to roll far.