Race the Track! The Time Challenge (Lesson Two)
By Kathy Scoggin, August 15, 2008
- Elementary School
45 – 60 minutes
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 utilize 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.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. 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. 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 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 will design and build a track that keeps the ball in motion for five seconds or longer. They will explore methods of using the materials given in innovative ways to both accelerate and decelerate their ball. This exploration also builds background knowledge to help them in the upcoming design challenges.
- Develop the notion that a variable is anything that you can change in an experiment that might affect the outcome and, in a controlled experiment, only one variable is changed, and the results are compared to a standard
- Develop students’ understanding of motion and forces
- Provide opportunity to utilize the design process to help plan and conduct an investigation
- Develop an understanding of science/design as a human endeavor in which the work of science/design relies on basic human qualities such as reasoning, insight, energy, skill, and creativity—as well as on scientific habits of mind, such as intellectual honesty, tolerance of ambiguity, skepticism, and openness to new ideas
- 8 pieces of track
- 7 connectors
- 6 small foam blocks
- 2 medium foam blocks
- small ball
- stop watch
- 1 can
- Time Challenge worksheet
- accelerate: to move faster; the rate of change of velocity
- decelerate: to move slower; a lessening of the rate of velocity
- incline: to be at an angle; a slope
- slope: used to describe the measurement of the steepness, incline, gradient, or grade of a straight line
- time: the measured or measurable period during which an action, process, or condition exists or continues
Set-up: 1. Set up materials station for small groups to collect what is needed 2. Make a large poster for students with materials listed and the challenge stated. 3. Have space available in the room for students to work in. Teacher presentation & motivation: 1. Overview discussion of Challenge Question:
- Tell the students, “Your challenge is to design and build a track that will keep your ball rolling for five seconds.
- Ask them, “Using only the materials provided, how can your group design a track that will control the speed of the ball traveling on the track?”
- Ask them, “What do you think you might try to speed up (accelerate) the ball?” Then ask them, “What do you think you might try to slow down (decelerate) the ball?”
- They should record at least three or four time trials
- They should draw an image of the track
- They should record what changed the speed of the ball in the T Chart
- What were the students’ successes?
- What did the students notice about how to control acceleration of the ball?
- What did the students notice about how to control deceleration of the ball?
- Where did the students find challenges?
- How did they solve those challenges?
Assessment is embedded in the work. Small groups will turn in their findings on the group worksheet. (Students might want to take a photo of their track to record their work through the unit as well as making a drawing.)
Enrichment Extension Activities
- Students create graphs to show the results speed results of their tests.
- Students convert cm/sec speeds to mph speeds.