Science Lesson Plan
Context Issues of the LessonUnit or Lesson Title:
Car Crash Safety: Momentum and Impulse
Grade Level 9 (but will be used in 8th as we follow high school
expectations currently)
Disclaimer: Students should have already covered Newton’s 1st and 2nd Laws and Action-Reaction Pairs
prior to lesson.
Topic/Theme/Nature
of the Investigation: Students will design, refine and build a car body to keep an “egg” driver safe in a collision with a wall at the end of a 250 cm track that is elevated four feet off the ground using the concepts of momentum and impulse to reduce the impact force(s) on both the car and the egg.
NGSS Performance
Expectation(s) HS-PS2-3: Apply scientific and engineering ideas to design, evaluate, and refine a device that minimizes the force on a macroscopic object during a collision.
NGSS Dimension 1 component
Constructing Explanations and Designing Solutions Constructing explanations and designing solutions in 9-12 builds on K-8 experiences and progresses to
explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.
Apply scientific ideas to solve a design problem, taking into account possible unanticipated effects.
NGSS Dimension 2
component Cause and Effect Systems can be designed to cause a desired effect.
NGSS Dimension 3 component
PS2-A: Forces and Motion
If a system interacts with objects outside itself, the total momentum of the system can change; however, any such change is balanced by changes in the momentum of objects outside the system. ETS1.A: Defining and Delimiting Engineering
Problems
Criteria and constraints also include satisfying any requirements set by society, such as taking issues of risk mitigation into account, and they should be quantified to the extent possible and stated in such a way that one can tell if a given design meets them.
Duration: 3 days for Engage and Explore
3 days for Explain
Planning Stages Within the 5-E Inquiry Model Engage PURPOSE:
to convey the context of the lesson(s)/unit by conveying an important Key Question to engage students in investigations that reveal their thinking to themselves and the teacher to record the initial ideas of students
to engage their interest
What is the teacher doing? What are the students doing?
***note: students are seated in groups of 4 around a table (or other such arrangement so students can collaborate with their shoulder partner first and, later, with their whole group).
1. As students walk in the room, have a picture of a car crash scene projected on an interactive white board, through a document camera, etc.
2. With their shoulder partner (as part of a table group of 4), students on the right hand side of the classroom will brainstorm in writing on a small whiteboard the types of forces and motion(s) likely involved in the pictured car crash.
3. Students on the left side of the classroom (with their shoulder partner) will brainstorm in writing any safety features of the car or road engineers that could have helped prevent injury to the passengers involved.
4. After 3-5 minutes (teacher will walk around to monitor student progress and can pose questions/statements to students who are stuck like:
What pushes or pulls on a car as it moves or stops?
If you are driving in a car and it stops suddenly, what happens?
Picture (in your mind) an area on a freeway or along a road that you drive---what do you see that is put there to help keep you safe?)
5. Students share out at their table group.
6. On a piece of chart paper divided into 2 sides (forces & motion/safety features), put together a class list adding or deleting based on student responses.
Explore PURPOSE:
to test ideas and develop knowledge using explorations, investigations, experiments to modify and record ideas as they change due to activities
to develop new questions and testable hypotheses
Activities (list) Driving Question 1. Masses in Motion Lab—2 parts
a. Students roll different sized ball bearings down an incline and measure the distance a barrier placed at the bottom moves on impact.
b. Students roll the same sized ball bearing down different inclines and measure the distance a barrier placed at the bottom moves on impact.
Materials Notes:
What is momentum?
For the incline try a ruler with a groove down the center with no binder holes or try using 2 rulers taped together with small groove to guide the ball bearings).
For the barrier, I use a Dixie cup (bathroom size) with a “door” cut on the “rampward” side. The ball bearing moves the cup when it hits the far side.
Suggestions:
Students can line up rulers even with the “door” of the ramp to measure the distance moved by the cup.
To lead students into thinking about impulse, have them compare (by listening and visually observing) what happens when the marble rolls into a fixed surface (large massed object, like a wall or one of those old, bulky, dusty
dictionaries or a wall, or a heavy piece of metal that makes a distinct noise when hit, but won’t move) with the cup.
Students graph the results on separate graphs for each independent variable (mass vs. distance cup moved and height of book vs. distance cup moved).
Students summarize their results in writing. 2) Impulse Quick Stations:
Teacher will divide the room into 2 halves. The group of students on one side will complete station one first, the other side will complete station two, then switch.
Station 1: Jump to Land--Students will each jump off the ground and land one of two ways—knees straight and knees bent. They will compare what is different and similar in both landings.
Station 2: Punch the Wall—Students will (with not too much “zest” punch a wall both with and without a pillow. They will compare what is different and similar in both impacts.
Identify increasing the time of a collision as a way to decrease the force. (Help students recognize everyday examples of impulse)
(consider showing “Models” of student products to help student identify characteristics of quality)
For Activity 1 (Masses in Motion)- Students graph the results on separate graphs for each
independent variable (mass vs. distance cup moved and height of book vs. distance cup moved) and summarize their results for class discussion. (handout not included)
For Activity 2 (Impulse Quick Stations): turn in “reflections” Explain
PURPOSE:
to answer the Key Question through student explanations
to provide students with relevant vocabulary, formal definitions and explanations of concepts Content Media: (written material, video, teacher lecture, technology)
1. Video: https://www.youtube.com/watch?v=yUpiV2I_IRI Understanding Car Crashes: It’s Basic Physics (from the Insurance Institute for Highway Safety)
---during and after viewing (some classes may require a second viewing to be able to better focus on the specific content) students will fill out the 3-2-1 Graphic Organizer (see
ancillary materials, attached) (1 day)
2. Students will need PC’s, Ipads, or Chromebooks to access
http://www.physicsclassroom.com/class/momentum/Lesson-1/Momentum
Working in partner’s teams will complete the three lessons:
Momentum
Momentum and Impulse Connection
Real-World Applications
As they progress, student will document their results on the “Checks for Understanding” and note reasons for/analyze initial errors and how they “relearned” that material so they now understood. (2 days)
Student Communication Product: (assessment, unit test, written report, oral presentation, poster, etc.)
1. Car Crash Video- 3-2-1 Graphic Organizer (see ancillary materials) 2. Students self-monitoring checklist (see attached).
Elaborate PURPOSE:
to extend students' conceptual understanding through application or practice in new settings Activities:
1. Practice Problems: Momentum and Impulse (in class and finish as homework) see ancillary materials.
2. Design and build a car body—students will work in teams of 4 to design and build a car body (to be affixed on wheelbases/chassis made of 2 x 4 and Pinewood Derby wheels) that will decrease the force of an impact and have little rebound. The design needs to keep a “raw egg” passenger safe upon collision with a wall at the end of a 4 foot high ramp (length about 250 cm) using only recycled/reused/repurposed materials brought in by the student team.
Before passing out portfolio packets to students, teacher will tell student engineers their job (problem) and the reason for it, intentionally leaving out many details.
Teacher will then ask students:
What do you need to know to solve this problem?
What questions do you have before you start?
The constraints and criteria of the project will then be introduced orally, before passing out packets.
Content Media: (written material, video, teacher lecture, technology) See attached handouts (in ancillary materials)
Extending/Application Questions for Whole/Small Group Discourse:
What would happen if we increased the height of the ramp?
Compare what would happen to the “egg passenger” with and without a seatbelt system. Is having the vehicle bounce off the wall in the collision “good” in terms of passenger injury? (think internal as well as external).
Where do you see Newton’s First Law applied in the simulation? Identify some action-reaction pairs in this simulation?
At what points are the forces acting on the car and/or egg balanced? Unbalanced? What do you notice about all of the vehicles that successfully kept the egg “alive”? How is your group working to solve problems that you encounter?
What are some “action words” that describe what you group did as you designed your car bodies?
Student Communication Product (assessment): (unit test, written report, oral presentation, poster, etc.)
1) Written multi-format quiz over momentum, impulse, real world applications. 2. Car Crash Portfolio
3. Educreations Video including digital photos of car designs and results (see attached outline)
Evaluate PURPOSE:
Learning Objectives Assessment Instrument 1. Students can predict how changes in mass
and velocity affect momentum.
2. Students can solve numerical problems using the mathematical relationship between impulse, force, time, mass, velocity, and (change in) momentum.
3. Students will identify and explain real-world examples of impulse and momentum. 4. Students will be able to work
Written Quiz (not included), practice problems, and self-monitoring checklist Written Quiz (not included), practice problems, and self-monitoring checklist
Written quiz and Car Crash Project Rubric
cooperatively with a team to design a solution to a problem.
5. Students will design, evaluate and refine a car body that minimizes the force on a passenger and the vehicle during a collision. 6. Students will use only recycled or repurposed (except tape or other materials or adhesives to put parts together) materials in their car body design and make it fit an existing chassis.
Teacher anecdotal notes
Car Crash Project Rubric and Portfolio
