Auto racing is an expensive and technically complex hobby, but it can be just as fun when it's scaled down to where the car can fit in your hand. CO2 dragster racing lets you do just that. Think you have what it takes to build a CO2 dragster? Let's find out!
Fill in the blank. CO2 dragster racing is often called "______ on steroids."
the Pinewood Derby
Because it's so similar to the Pinewood Derby, where small wooden cars are raced on a downhill track, CO2 dragster racing is called the "Pinewood Derby on steroids." That's because the cars are similar, but CO2 Dragsters use propulsion instead of gravity to race.
Fill in the blank. It's Newton's ______ law that's responsible for the gas rapidly escaping from the CO2 cartridge to push the car down the track.
In terms of physics, the rapidly escaping gas causes Newton's Third Law of Motion to occur -- for every action there is an equal or opposite reaction. The rearward motion of the gas pushes the car forward in this case, overcoming inertia, or the resistance to movement.
How do you overcome friction when designing and building your CO2 dragster?
Add more paint
Use spoilers and body add-ons
Make sure the moving parts are free to rotate and don't rub on the body
Because the dragster has parts moving against one another, friction is created. You can help reduce it by making sure the axles are free to rotate, and that the wheels and tires are not rubbing on the car body.
How does the racing actually happen with CO2 dragsters?
They're hooked up to a launch pod which breaks the CO2 cartridge seal on all cars at the same moment.
Once the cars are ready to race, the sealed cartridge is inserted, and they are placed on the starting grid. Often, they're hooked up to a device called a launch pod, which punctures the cartridges of two or more cars at the same time. These devices can also be built by hand using some wood and nails to puncture the CO2 canisters.
They're rolled downhill and the CO2 cartridge activates automatically.
What can students learn from doing CO2 dragster racing in their science classes?
Friction, inertia and mass
Newton's Laws of Physics
All of the above
Building a CO2 dragster can be a great project at schools because it teaches students about aerodynamics, as well as things like friction, inertia and mass. It can also be done as a competitive event or hobby.
What do you look for when you put the car into a wind tunnel?
As many swirls as possible
The speed of the air flow
A smooth flow of air
By putting your car into the wind tunnel and putting a fog vapor into the air stream, you can track how air flows over the car's body. You want a smooth flow of air free of swirling currents called eddies. If you have too many of those, you may want to use sandpaper to smooth out the design, or go with a new one altogether.
Why is a wind tunnel so helpful in testing for drag?
Airflow is hard to measure with the naked eye
It's hard to tell with the naked eye just how much drag your CO2 car will face. For that reason, you may want to opt for a wind tunnel. Believe it or not, there are small wind tunnels available designed to test models.