用办公和工艺材料来搭建汽车。（或者，如果你不想自己做，也可以去买个中型玩具车） 在线搜索“气球车”或“橡皮筋车”，您会发现许多设计理念。 一般来说，您将需要准备：
- 用作汽车轮子的东西，如 CD 或塑料饮料盖
- Set up “speed bumps” for your car to drive over. For example, tape several straws or pencils to a tabletop, parallel to one another and a few inches apart.
- Pull the car quickly across the speed bumps. What happens?
- Now try to design a suspension for your car to prevent the packing peanuts from falling out of the box. For example, you could suspend the cardboard box from rubber bands. This is where the engineering design process really comes in to play!
- Once you have built your suspension, try pulling your car over the speed bumps again. Try to do it at the same speed. What happens this time? Do fewer packing peanuts fall out?
- Don’t get discouraged if your suspension doesn’t work on the first try! The engineering design process is iterative, meaning engineers often go back and redesign, rebuild and retest their devices to improve them. There are many different things you can tweak about your design. For example:
- Try changing the type of rubber bands. What happens if you use thicker or thinner rubber bands, or longer or shorter ones?
- Try changing the tightness of the rubber bands. What happens if the box is hanging from them loosely or if the rubber bands are pulled tight?
- Try changing the weight of different parts of the car. (Weight has a big impact on vibrations.) For example, what happens if you tape a bunch of coins to the cardboard box to make it heavier? What happens if you tape the coins to the frame of the car instead?
- Keep iterating and tweaking your design. Can you get to a point where no packing peanuts fall out of the box?
Observations and results
You should find that when you attach the cardboard box directly to the frame of your car, many of the packing peanuts are tossed out of the box when you pull it over the speed bumps. This occurs because the vibrations from the wheels are transferred directly to the cardboard box. This would be like riding in a car with no suspension—quite an uncomfortable ride! When you add a suspension, it helps absorb some of the vibrations, so the cardboard box does not bounce up and down as much and doesn’t toss out as many of the packing peanuts. It might take some tweaking, however, to get your suspension working well. The stiffness (thickness/length/tightness of the rubber bands or springs) and weight of an object (for example, adding coins) have a big impact on how it reacts to vibrations. Real engineers carefully design a car’s suspension to optimally absorb vibrations on the road, just like you did in this project!
This project was inspired by the Trash Sliders activity, by Larry Richards, via eGFI.