Applied Science - Technology (6B)

  • Investigating aerodynamic design.
  • Identifying aerodynamic design.


  • aerodynamic
  • balls (soccer, football, ping pong,
    or any other ball used in sports)
    vehicles (toy cars, motor cycles,
    construction machines, etc)
  • How Things Work by Steve Parker

Students explore designs that are aerodynamic.


Students hear about cars that are aerodynamically designed in many advertisements on television. They probably have a sense of what it means, because most of these cars are sleek and low. Cars are designed this way to minimize resistance and allow them to go faster. The overall design is streamlined which "cuts" the air. When a vehicle is aerodynamically designed it can save fuel, because it takes less energy to travel. For race cars and road cars this is important. However some vehicles do not want to go faster as much as they need to accomplish a certain goal. For instance, a farm tractor is not designed to go fast, it is designed to do a job.

The outside of a car is designed to make use of aerodynamics, but the inside of the car tries to make an efficient machine that will do work. There are many other laws of physics in just one vehicle. You may want to go over how a car works just to illustrate to students that cars are a physical design created by engineers.

A car is a complex compound machine, that is fueled by gasoline to create motion. In a car, the engine is responsible for producing the power that causes the wheels to turn. The engine turns a rod called a crankshaft which is connected to the drive shaft which in turn is connected to the axle which of course is connected to the wheels.

Gasoline is pumped into the gas tank of the car. From the gas tank, the fuel travels through the fuel line and reaches either the carburetor or fuel injector. From this point the gas flow is controlled by the amount of pressure placed on the accelerator. The fuel is converted into a mist much like a perfume by the carburetor. This "perfume" is then released into the cylinders where it is compressed, ignited, and exploded. Each time an explosion takes place the pistons are forced down, causing the crankshaft to turn. With each turn of the crankshaft comes a turn of the drive shaft and with each turn of the drive shaft, comes a turn of the axle and consequently the wheels.

A car is a complicated and complex machine that is dependent upon the laws of physics for both efficiency and performance. Nearly all the laws of physics can be found in the workings of an automobile. Friction between the rubber tires and asphalt ground is the reason the car moves (aside from all the workings of the engine). To better improve friction, tires are built and designed with tread patterns that grip the asphalt road more efficiently.

Aerodynamics is also a great factor when it comes to designing cars. Air resistance can contribute greatly to low gas mileage and poor efficiency. As a result, car manufacturers design automobiles with pointed fronts, rounded bodies, and streamlined patterns. With these designs the air can be "cut" so it does not act like a block stopping the car. A good way to test the notion of air resistance is to put a hand out of a car when going down the freeway. A vertical hand pointing straight up will encounter great air resistance while a horizontal hand will hardly encounter any. This is the reason cars are pointed in the front and not flat.

Work done by the engine is transferred to different parts of the car through gears and levers until this work reaches the axle. Once the work has reached the axle the tires can be turned and the car can move. For this work to be created, however, requires the presence of such items as carburetors, pistons, crankshafts, spark plugs, gasoline, and many other components. A car is about the best example of all the forces of physics coming together for one purpose, motion.

  1. This lab allows students to look at a model helicopter, airplane, tractor, trucks, and automobile. They will determine what the design is trying to accomplish. In the previous labs on design and motion of fluids, students looked at some of the background reasoning for large vehicles.
  2. The key objective of this lab is for students to start realizing that many of the products we use everyday all had great thought, design, and scientist behind the object. You can add any other models that you may have so students have a chance to think about the design. This lab emphasizes aerodynamic design and not how the inside of the vehicle works.
  3. You may also want to look at How Things Work to see how the other vehicles that are used in this lab, work.
  4. Part of this lab looks at the design of balls. Yes, even balls are designed. For this part you might want to add a football, soccer, and basketball from the gym. Room is left on the lab sheet for this purpose.
  5. The answers can vary with your students. However, they should notice that land vehicles are not as aerodynamically designed as airborne vehicles. A tractor does not really care about aerodynamics as much as to accomplish work. A truck is for more traction and is considered a work vehicle. Large tires on a vehicle help the vehicles have traction, not to go fast.
  6. Different balls are designed for different sports. The football is designed to be thrown, notice the streamlined shape. The basketball and soccer balls are not aerodynamically designed but are designed to work well with the hand (basketball) and foot (soccer). Notice that a golf ball isn't like a ping pong ball. The little "pimples" are designed to be more aerodynamic. A ping pong ball would not go too far if hit by a golfer!

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