Race the Track! Jump the Gap (Lesson Four)
By Kathy Scoggin, February 23, 2009
- Elementary School
Students and their teachers are introduced to basic physics concepts and the idea of variables through use of Mattel™ Hot Wheels tracks and steel balls. Students will use the design process to explore force and motion. This series of lessons allows students and teachers to work through the design process in order to investigate physical science and experimental design concepts. It highlights the design process as a tool allowing students to approach issues in a meaningful and productive way. This unit follows a learning cycle of Focus - Explore - Reflect - Apply. The cycle is followed throughout the entire unit as well as within individual lessons. It allows students to observe phenomena during their investigations which will lead them to ask questions and design systems in which to explore answers to their questions - and on to further questions.
Science Standard 10. Level II. Understands forces and motion 2. Knows that the Earth’s gravity pulls any object toward it without touching it 5. Knows that when a force is applied to an object, the object either speeds up, slows down, or goes in a different direction 6. Knows the relationship between the strength of a force and its effect on an object (e.g., the greater the force, the greater the change in motion; the more massive the object, the smaller the effect of a given force) Standard 11. Level II. Understands the nature of scientific knowledge 2. Knows that good scientific explanations are based on evidence (observations) and scientific knowledge 4. Knows that scientists review and ask questions about the results of other scientists’ work Standard 12. Levels Pre-K and II. Understands the nature of scientific inquiry 1. Knows that scientific investigations involve asking and answering a question and comparing the answer to what scientists already know about the world 2. Knows that scientists use different kinds of investigations (e.g., naturalist observation of things or events, data collection, controlled experiments), depending on the questions they are trying to answer 3. Plans and conducts simple investigations (e.g., formulates a testable question, plans a fair test, makes systematic observations, develops logical conclusions) 5. Knows that scientists explanations about what happens in the world come partly from what they observe (evidence), partly from how they interpret (inference) their observations
Students investigate the intermarried concepts of variables and design. The focus is on developing recognition of the variables inherent in their track systems and understanding how manipulations with variables (i.e. design of the track system) can/will affect the trajectory of the ball. Students will:
- learn how to recognize variables in a system and investigate how manipulating the variables changes the outcome of a trial
- systematically collect and record data for later analysis
- develop an understanding of the interplay of the forces of gravity, force, and speed as it relates to landing a projectile on a specified target (when a projectile has the correct amount of energy it will land on target)
- recognize the design process as a creative challenge employing the skills of observation, research (data collection), problem solving, and sharing results and connect it to the process of setting up an investigation, manipulating variables and collecting data to achieve a specified outcome
The variables within the track system at this point are: Height of the launch (release point of ball) Width of the gap Size (weight) of ball
Each group of students will need:
- track pieces (5 short)
- connectors (3)
- c-clamp or masking tape
- jump (launch and catch pieces)
- meter stick
- masking tape
- can (to be used as a target)
- large and small steel balls
- Jump the Gap Data Sheet
- Frame of Reference Chart
- Design Process Poster
- design: plan something for a specific role or purpose or effect; the act of working out the form of something
- variable: anything you can change in an experiment that might affect the outcome
- controlled experiment: a form of scientific investigation in which one variable, termed the independent or control variable, is manipulated to reveal the effect on another variable, termed the dependent or responding variable, while all other variables in the system are held fixed
- speed: distance travelled per unit time
- distance: the property created by the space between two objects or points
- projectile: any object propelled through space by the exertion of a force which ceases after launch (in this case, the steel ball)
- potential energy: the mechanical energy that a body has by virtue of its position; stored energy
- kinetic energy: the mechanical energy that a body has by virtue of its motion
- friction: the resistance encountered when one body is moved in contact with another
- gravity: the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface
- acceleration: a rate of increase of velocity
- system: a set of related objects that can be studied in isolation
1. Teacher Presentation and Motivation: Draw a Frame of Reference chart on large paper. Use this “Thinking Map” ? as a tool to gather prior knowledge with your students:
- In the center circle record the topic.
- Invite the group to brainstorm what they know about design as you record their answers in the outer circle.
- Next, ask them how they know what they know – i.e. “Learned in another class”, “My mom is a designer”, “I saw a program on TV”, etc. Record in the outer “frame”. Discuss.
- Compare the results from the small and large ball.
- How did the height of the release point affect the size the gap successfully jumped?
- What variable seemed to make the most difference in getting the ball to jump the gap?
- “This graph shows _____________________________________, therefore we think ________________________________.”
- I am curious about ________________________.
- It surprised me that ________________________.
- I wonder what would happen if_________________.
- How does __________affect __________________?
Formative assessment is embedded in the work and the group discussions. Further assessment will occur as they work to solve track design challenges in following lessons.