Cars: Engineering for Efficiency
Students learn how the aerodynamics and rolling resistance of a car affect its energy efficiency through designing and constructing model cars out of simple materials. As the little cars are raced down a tilted track (powered by gravity) and propelled off a ramp, students come to understand the need to maximize the energy efficiency of their cars. The most energy-efficient cars roll down the track the fastest and the most aerodynamic cars jump the farthest. Students also work with variables and plot how a car's speed changes with the track angle.
Example model cars built by elementary school students.
The energy use and pollution associated with transportation is one of the largest issues facing society today. By building energy-efficient cars, engineers can lower the negative impacts that cars have on the environment and ultimately help improve our lives. The energy efficiency of a car is affected by a variety of factors, including size, aerodynamics, weight, and the rolling resistance of the wheels. Engineers must know all about these factors to design better cars.
After this activity, students should be able to:
- Describe the characteristics that affect a car's energy efficiency.
- Explain how rolling resistance affects a car's energy efficiency.
- Describe how a car's shape and size are related to aerodynamics.
- Explain the steps of the engineering design process.
- Explain the difference between an independent and dependent variable.
- Plot the results of a simple experiment on a graph.