Unit Title: Solar Cars
Lesson Title: Gear Ratios, Kinetic Energy and Forces
Date Developed/Last Revised:
Lesson Author(s): John Constantinou, Kara Suzuka
Lesson #: 2
Grade Level: Middle School
Primary Content Area: Math, Science
Time Frame: 2 hours
PLANNING (Steps 1, 2, & 3)
1. Standards/Benchmarks and Process Skills Assessed in this Lesson:
● 6.RP.A.1: Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities.
● 6.RP.A.2: Understand the concept of a unit rate a/b associated with a ratio a:b with b ≠ 0, and use rate language in the context of a ratio relationship.
● MS-PS2-2: Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object.
● MS-PS3-1: Construct and interpret graphical displays of data to describe the relationships of kinetic energy (KE) to the mass of an object and to the speed of an object. (KE = 1/2 mv^2, but the clarification statement and evidence statement, it isn't mandatory that they get to the final equation, just the proportionalities between KE to m, and KE to v^2)
2A. Criteria- What Students Should Know and Be Able to Do:
Students can-
● Use information from their investigations to determine the effects of gear ratios on power and speed for cars, bikes, etc.
● Use ratio language to describe a relationship between 2 quantities (speed =d/t, and gear ratios)
● Describe the relationship of KE to Mass and speed● Describe the forces acting on the car. F=m*a
2B. Assessment Tools/Evidence:
Formative:
● Ratio Pre-Assessment: https://goo.gl/cYpiRV● Science Kinetic Energy Pre-Assessment: https://goo.gl/ZSEsHJ
Summative: Can use the formative pre-assessment as a post assessment to measure student learning
3. Learning Experiences (Lesson Plan)
Materials:
● Gear Investigation Car from STEM Pre-Academy (Insert Link), with different gear ratios
and movable motor. http://kelvin.com/kelvina-gear-car-kit/
● Timers● Balance● Weights to add to cars (fishing lead works well)
Handouts/Other Resources: (please attach copies)
● Gear ratio background information powerpoint● Photo of axle and gear setup● Gear Generator (simulator)● Gear Basics (Video)● Gear ratio test car build● The story of kinetic and potential energy Video: https://www.youtube.com/watch?
v=7K4V0NvUxRg● Kinetic Energy Resources- Energy Skate Park Simulator:
● https://phet.colorado.edu/en/simulation/legacy/energy-skate-park
Procedure:
● Investigation: Gear Ratio Kinetic Energy, Force and Investigation● Students will measure mass and speed/acceleration of their cars to explain the
relationship of KE to speed and mass and how an object’s motion depends on the sum of the forces on the object.
● Students will use knowledge from the investigations on Solar Panels and Gear Ratios to engineer a solar powered car that can travel quickly on flat ground without a load and
modify the car to carry a load (lead fishing weights). Engineering Design of Solar CarHomework Activity (Optional):
● Look for other simple machines around the home that use gears.● Make a list of machines that use gears and describe:
o The gear ratioo The purpose for using gears for the specific application. Explain the
“mechanical advantage” that using gears provides for the machine’s application.