After we have already shown you in an experiment how to build a water rocket, we will show you in this instruction how to build a rocket car. Have fun and good luck with your work!
For the rocket car you need:
- 1 empty plastic bottle
- 4 round beer mats
- 2 drinking straws
- 2 wooden shish kebabs
- Clear cover
- 3 corks
- Small screw eye
- 2 m twine
- Hot glue
- Pointed knife
- Pencil and ruler
- vinegar (about 100 ml per start; best not to use the expensive balsamic vinegar from the kitchen shelf). Cleaning vinegar will do)
- Baking soda (about 20 g per start)
This is how the rocket car is built:
1: before you start, find some of the cork choose the one that fits best as a cap in the bottle – so that you need some force to push it in. Put it aside. Cut the remaining corks into four equally thick slices each.
2: Fill the bottle a quarter full with water and place it on a flat surface. This spirit level help yourself to mark the points where you have to drill holes at the same height. At the front and back, the distance is 5 cm from the bottom of the bottle for the front axle, and 10 cm from the opening of the bottle for the rear axle.
3: carefully drill the holes in the plastic. The best way to do this is to heat the tip of the knife over a candle beforehand. The holes should be so big that the drinking straws just fit through it.
4: push the straws through the candle and shorten them so that the ends protrude by 3 cm each. Seal the holes carefully with glue from. Blow into the bottle to check if air is still escaping somewhere.
5: mark the center on each beer cap. then put a cork disk, a beer cap and another cork disk on a wooden skewer. Push it through one of the drinking straws and then again put a cork disk, a second beer cap and another cork disk on it. Repeat the whole thing with the second spit. The four wheels should sit firmly on the axles, held in place by the cork discs. If in doubt, use some glue to help you.
6: from the cork, which you put aside at the beginning, you make a cartridge, into which the baking powder charge is filled before the launch. Screw the eyelet into one of the ends of the cork and tie the string to it.
7: cut a piece out of the clear cover, 8 cm long and wide enough to fit around the cork once. glue the cork and the plastic foil together – so that the cartridge is a bit slimmer towards the end.
The start of the rocket car:
8: look for a flat place outside test track. then add 100 ml of vinegar to the bottle and 20 g of baking soda to the cartridge. Push the cartridge into the opening without mixing the powder and vinegar. Attention: the tighter the cork sits, the more powerful the car will go off. However, if it sits too tight, nothing may happen! Lift the back of the car so that the powder trickles into the vinegar. Shake the vehicle and quickly put it in the launch position.
9: now vinegar and baking soda react with each other. This creates carbon dioxide and creates overpressure inside the bottle. The cork is then forcefully ejected from the opening, the car shoots in the other direction – and you can guess what the string is for: you can use it to hold the cartridge in place. Don’t be surprised: it can happen that the cartridge breaks at startup. then simply stick a new piece of foil around the cork.
How a rocket works?
Rockets are powered by the so-called recoil principle powered. This was discovered over 300 years ago by the english scientist isaac newton. Newton noticed that every force produces an opposing force: if you kick the edge of the pool, your body will move in exactly the opposite direction.
Nothing else happens during a rocket launch. Inside the rocket propellant mixture the rocket is ignited, producing gases that shoot out of the engines with incredible pressure – and push the rocket off the ground, so to speak. By the way, this principle still works when there is no ground to push off from. Even in a vacuum. The rocket engine is therefore the most common in space travel. We filmed the first launch – here’s the video.