What I did
On our water bottle rocket, we used 2 bottles, 3 plastic wings, a birthday cone hat, some tape, yarn, and two trash bags. As you can see below, there are sketches of the water bottle rocket. If you look at the sketches, there are two parachutes, 3 wings, and a smooth surface for the bottle. These all had reasons, and they will be explained later on. Anyways, we taped the bottom part into the cut out body part of the bottle that has the whole other bottle. So, the bottoms of the bottles are touching each other. This way, we could put our parachutes inside. Also, we taped plastic wings to the sides and made holed to tie the strings of the parachutes.
From below, you can see that we tried to plan and draw out our ideas for the rocket.
From below, you can see that we tried to plan and draw out our ideas for the rocket.
What I Learned
When we tried to launch our parachutes, I learned several things. First of all, how you fold the parachute was extremely important. The way we folded it was to pinch it's middle part and make it straight it as possible. Then, we folded in a zigzag and carefully put it in the bottle so the parachute could open quickly when it was up in the air. Another thing I learned was that you need to make the cone and fins pointed so it could decrease the air friction as much as possible. The last thing that I learned was that you needed to put just the right amount of water. If there was too much, it would not go high enough because of the weight. However, if there was too little, the rocket didn't go high enough too since there was not enough pressure (fuel for the rocket).
Concepts
Newton's 1st Law
As the rocket is launched into the air, inertia is used upon this rocket so it tries to make the rocket go further upward. However, because of many other friction and gravity, the rocket soon comes down. So, the best way we could increase the inertia was reducing the frictions as much as possible. The things below were more things I tried to make the inertia the best.
Newton's 2nd Law
If the force put on the rocket is stronger, the rocket would go higher. However, the mass of the rocket may reduce the acceleration too. So, the amount or water put in the rocket needed to be thought of a lot. From the many experiments we went through, we figured out that the best for the 2L bottle was in between 700ml to 800ml. This way, there is not that much water that weighs down the rocket, but enough to push the rocket as much as possible.
Newton's 3rd Law
When the rocket blasts off into the air, it flies. This is because the water pushes downward, and reaction for this was the ground pushing back. Because of this, the rocket flies upward. Well, this shows that just the right amount of water is needed since it must be enough to push the rocket the highest, but it needs to be light too. So, considering how much water you put in the rocket is extremely essential.
Sliding Friction
The rocket has a lot of influence on sliding friction since the smoother the surface is, the further the rocket goes up. The best way we could solve this problem was to make the surface of the rocket as smooth as possible by putting the tape on properly with a lot of patience.
Fluid Friction
As the rocket flies up, the air will try to push it back. As the surface is flatter, there will be more fluid friction. Some ways we used to reduce this friction was to make the cone and the fins. These objects helped the rocket cut though the air and fly with less friction slowing it down. Also, we tried to make the surface of the bottle as smooth as possible so there wouldn't be anything in the way of the fluid friction.
Static Friction
Static friction are caused when the parachutes opens. As the parachute opens in the sky, the air that was staying starts to go inside the parachute and this results in making the rocket go slower toward the ground. The static friction makes the parachute work. So, the best way to do this was to make a big parachute. However, since we wanted to slow the fall more, we just made 2 parachutes. Even though we had to be very careful so the strings don't tangle, we had pretty good records because of the 2 parachutes.
Gravity
If the rocket itself weighs a lot, the rocket won't fly up as high. Because of gravity that pulls down the rocket, we tried to reduce the gravity on the rocket. What we did to solve this problem was to make a parachute so the rocket could fall slowly. Since how high the rocket goes up is extremely important, we tried to reduce the weight as much as possible.
As the rocket is launched into the air, inertia is used upon this rocket so it tries to make the rocket go further upward. However, because of many other friction and gravity, the rocket soon comes down. So, the best way we could increase the inertia was reducing the frictions as much as possible. The things below were more things I tried to make the inertia the best.
Newton's 2nd Law
If the force put on the rocket is stronger, the rocket would go higher. However, the mass of the rocket may reduce the acceleration too. So, the amount or water put in the rocket needed to be thought of a lot. From the many experiments we went through, we figured out that the best for the 2L bottle was in between 700ml to 800ml. This way, there is not that much water that weighs down the rocket, but enough to push the rocket as much as possible.
Newton's 3rd Law
When the rocket blasts off into the air, it flies. This is because the water pushes downward, and reaction for this was the ground pushing back. Because of this, the rocket flies upward. Well, this shows that just the right amount of water is needed since it must be enough to push the rocket the highest, but it needs to be light too. So, considering how much water you put in the rocket is extremely essential.
Sliding Friction
The rocket has a lot of influence on sliding friction since the smoother the surface is, the further the rocket goes up. The best way we could solve this problem was to make the surface of the rocket as smooth as possible by putting the tape on properly with a lot of patience.
Fluid Friction
As the rocket flies up, the air will try to push it back. As the surface is flatter, there will be more fluid friction. Some ways we used to reduce this friction was to make the cone and the fins. These objects helped the rocket cut though the air and fly with less friction slowing it down. Also, we tried to make the surface of the bottle as smooth as possible so there wouldn't be anything in the way of the fluid friction.
Static Friction
Static friction are caused when the parachutes opens. As the parachute opens in the sky, the air that was staying starts to go inside the parachute and this results in making the rocket go slower toward the ground. The static friction makes the parachute work. So, the best way to do this was to make a big parachute. However, since we wanted to slow the fall more, we just made 2 parachutes. Even though we had to be very careful so the strings don't tangle, we had pretty good records because of the 2 parachutes.
Gravity
If the rocket itself weighs a lot, the rocket won't fly up as high. Because of gravity that pulls down the rocket, we tried to reduce the gravity on the rocket. What we did to solve this problem was to make a parachute so the rocket could fall slowly. Since how high the rocket goes up is extremely important, we tried to reduce the weight as much as possible.