Project #3: Water Bottle Rocket
Involving Newton's three laws , Gravity, Static, sliding, and fluid friction + Free fall
What I Did:
We had to make a rocket out of a 2 liter carbonated soda bottle that would be able to stay in the air for the longest time and land efficiently.
Specifications:
The rocket must be constructed of the following materials:
• 2 liter CARBONATED bottle
• have a 2.2 cm mouth/nozzle opening
The rocket may be constructed with the following:
• A nosecone
• Decoration
• Fins
• Adhesives
• Recovery system
The rocket may NOT be constructed with the following:
• Superglue on the main body bottle (changes the chemical makeup and
damages the integrity of the bottle)
• Hot glue on the main body bottle (melts the bottle and damages the
integrity of the bottle)
• Pre-fabricated body part made for that purpose.
• Anything made of metal.
Other requirements:
• The rocket must fit on the launcher (available during design and
construction).
• The rocket may not come apart during the launch or upon impact.
• The bottle’s integrity may not be compromised in any way.
• Do not paint or place anything inside the bottle except water.
• You must leave a window near the nozzle/opening of the bottle so I
can tell when it is pressurized
• Do not cut the bottle that is part of the main body.
• All propulsion energy must originate from the air/water pressure
combination provided at the time of launch. Other forms of kinetic
and potential energy may not be used to deploy rocket components.
No pyrotechnics, pressurized gases, or remote control will be allowed.
• The maximum extended length of the rocket and its components (nose
cone, recovery system, fins, etc.) may not exceed 3 meters in length.
Outcome:
My group made our body by taking our 1st soda bottle and attaching the tube of a 2nd soda bottle to the end of the 1st. We also took the bottom of the 2nd soda bottle and sat it on top of the bottom of the first, so it made a compartment for the parachute. When we first made our nosecone, we used the top of the 2nd bottle, but then discovered that the nose cone had to be bigger than the body of the rocket so that it did not let out any air. We originally wanted to use a parobolic nose cone, which is the kind that they use of airplanes, but couldn't find any materials in that shape. We then used a nose cone shaped like a sports cone. We made our fins out of laminated cardboard paper, which we cut into trapezoids with two right angles, and set them equidistant around the circumference of the body of the bottle. Our parachute was made out of a garbage bag with yarn tied to it. The yarn was equally distant from each other, and grouped into groups of four to be tied to the body of the bottle. The yarn was about twice the length of the body of the bottle. We put about 1000 mls of water into our rocket. Our Rocket won 2nd place in the second tier of the competition. Our longest time was 6.9 seconds. We had some complications with our parachute deploying. Our parachute did not actually deploy until our final launch.
What I learned:
Concepts:
Newton's First Law:
Essentially, inertia is Newton's First Law of Motion. I'm sure if you've been anywhere near a science classroom, you are able to rattle off this law. Any object in motion stays in motion and any object at rest stays at rest unless acted on by an unbalanced force. It is quite simple really. Let's say, you have a ball and you throw it. That ball will stay in motion, until it is acted upon an unbalanced force, which in this case would be gravity. As learned, gravity will pull that ball back down towards Earth. Now, lets take up a level. You're in a car, cruising down the road, when suddenly, a truck comes out of nowhere and is about to hit you. You slam on the breaks. If you have your seat belt on, you will be stopped from going through the windshield by the force of the seat belt. But, it's bad news if you don't. Despite the fact that your car has stopped, inertia will keep you moving until you hit something, which, unluckily for you, would probably be the pavement. How does this apply to the water bottle rocket? After the rocket is launched, it is moving through the air, but it is being slowed down by another external force that is being applied to the car. More than one force was being applied, including gravity, static friction, and fluid friction.
Newton's Second Law:
The Second Law of Motion states that force equals mass times acceleration, or f=ma. Let's say you have a really tiny book, maybe 50 pages in length, and you have a huge encyclopedia, ranging anywhere from 700 to 800 pages. It takes less force for the tiny book to move at the same acceleration rate as the encyclopedia because the encyclopedia has a bigger mass. Therefore, the smaller something is, the less force it takes for it to accelerate. This means that the amount of force depends on the amount of mass the car has and the amount it accelerates. This law has to do with the water bottle rockets because the amount of acceleration that was applied to the rocket depended on the amount of water that was put into the rocket and how big or small the rocket was. To ensure that our rocket would go really high, we tried to make our rocket as light as possible and to add lots of water. We put 1000 milliliters into our rocket, which is a lot of force. In favor, our rocket accelerated a great amount because our rocket did not have a huge amount of mass, but had a lot of force.
Newton's Third Law:
Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. No, Newton was not talking about when you do something wrong and your mom punishes you. Think of it this way: if you're on a diving board, and you want to jump into the pool, you jump and push off against the diving board. I know it is hard to wrap your head around, but the diving board actually pushed back against you. Crazy, right? Another way to think about it is if you're in a row boat. When you row, you push the paddle against the water. In return, your boat moves forwards or backwards. This law is applied to the rocket because the compressed water pushes against the ground when launched. In return, the ground pushes against the water, which exerts the rocket high into the air.
Sliding Friction:
Sliding friction is the type of friction when something is resisting to the slide. Think of a skater ice skating. When the skater skates, are they more likely to go faster when they're skating on a really smooth surface, or on a really bumpy surface? Obviously, a skater wants the smooth surface because there is less sliding friction. The smoother a surface is, the less sliding friction there will be. Sliding friction applies to the parachute of the rocket. When the parachute deploys, it slides against the insides of the body of the rocket. To ensure that the rocket will come out really easily, the insides had to be as smooth as possible. They couldn't have random pieces of duct tape and the bottle could not be bent. Sliding friction also comes into play when the rocket comes off of the launcher. As the rocket comes off the launcher, the mouth of the bottle slides against the mouth of the launcher.
Fluid Friction:
Fluid friction has to do with anything that is moving through a liquid or gas. While moving through a liquid or gas, the water and air particles hit against the object, causing it to slow down. Think about when you're swimming, and when you stand in the shallow end of the pool and try to walk through the water. It is more of a tedious and longer task to walk through water than if you weren't walking in water. This is because water particles are hitting against your body and resisting you from moving faster. This has to do with our water bottle rocket because the rocket moves through the air after it is launched. In order for our rocket to be effected as little as possible by fluid friction, we used a nose cone so that the air would hit our rocket with minimum force.
Gravity:
When most people think of gravity, they think of it as this invisible force that pushes objects, including us, around. But, in reality, Gravity does not push things around. Instead, it is the element that pulls objects of a smaller mass to objects of a greater mass. The most common example that can be though of actually involves you. You see, everyone and everything here, on this planet, is currently being pulled toward Earth. If you hadn't already figured it out, our planet is HUGE, and you're just a measly hundred to two-hundred poundish body of mass. GRAVITY is the force that keeps your feet planted on the ground. Also, if you're wondering, the Earth is being pulled by the sun's gravitational force, so we are able to spin around the sun and be happy and alive and whatnot. Gravity can be applied to this project because gravity is the force that pulls the rocket back down towards earth after it is launched. Free fall would be the body of the rocket coming down from the air. But, because we wanted our rocket to stay in the air as long as possible, we used a parachute.
We had to make a rocket out of a 2 liter carbonated soda bottle that would be able to stay in the air for the longest time and land efficiently.
Specifications:
The rocket must be constructed of the following materials:
• 2 liter CARBONATED bottle
• have a 2.2 cm mouth/nozzle opening
The rocket may be constructed with the following:
• A nosecone
• Decoration
• Fins
• Adhesives
• Recovery system
The rocket may NOT be constructed with the following:
• Superglue on the main body bottle (changes the chemical makeup and
damages the integrity of the bottle)
• Hot glue on the main body bottle (melts the bottle and damages the
integrity of the bottle)
• Pre-fabricated body part made for that purpose.
• Anything made of metal.
Other requirements:
• The rocket must fit on the launcher (available during design and
construction).
• The rocket may not come apart during the launch or upon impact.
• The bottle’s integrity may not be compromised in any way.
• Do not paint or place anything inside the bottle except water.
• You must leave a window near the nozzle/opening of the bottle so I
can tell when it is pressurized
• Do not cut the bottle that is part of the main body.
• All propulsion energy must originate from the air/water pressure
combination provided at the time of launch. Other forms of kinetic
and potential energy may not be used to deploy rocket components.
No pyrotechnics, pressurized gases, or remote control will be allowed.
• The maximum extended length of the rocket and its components (nose
cone, recovery system, fins, etc.) may not exceed 3 meters in length.
Outcome:
My group made our body by taking our 1st soda bottle and attaching the tube of a 2nd soda bottle to the end of the 1st. We also took the bottom of the 2nd soda bottle and sat it on top of the bottom of the first, so it made a compartment for the parachute. When we first made our nosecone, we used the top of the 2nd bottle, but then discovered that the nose cone had to be bigger than the body of the rocket so that it did not let out any air. We originally wanted to use a parobolic nose cone, which is the kind that they use of airplanes, but couldn't find any materials in that shape. We then used a nose cone shaped like a sports cone. We made our fins out of laminated cardboard paper, which we cut into trapezoids with two right angles, and set them equidistant around the circumference of the body of the bottle. Our parachute was made out of a garbage bag with yarn tied to it. The yarn was equally distant from each other, and grouped into groups of four to be tied to the body of the bottle. The yarn was about twice the length of the body of the bottle. We put about 1000 mls of water into our rocket. Our Rocket won 2nd place in the second tier of the competition. Our longest time was 6.9 seconds. We had some complications with our parachute deploying. Our parachute did not actually deploy until our final launch.
What I learned:
Concepts:
Newton's First Law:
Essentially, inertia is Newton's First Law of Motion. I'm sure if you've been anywhere near a science classroom, you are able to rattle off this law. Any object in motion stays in motion and any object at rest stays at rest unless acted on by an unbalanced force. It is quite simple really. Let's say, you have a ball and you throw it. That ball will stay in motion, until it is acted upon an unbalanced force, which in this case would be gravity. As learned, gravity will pull that ball back down towards Earth. Now, lets take up a level. You're in a car, cruising down the road, when suddenly, a truck comes out of nowhere and is about to hit you. You slam on the breaks. If you have your seat belt on, you will be stopped from going through the windshield by the force of the seat belt. But, it's bad news if you don't. Despite the fact that your car has stopped, inertia will keep you moving until you hit something, which, unluckily for you, would probably be the pavement. How does this apply to the water bottle rocket? After the rocket is launched, it is moving through the air, but it is being slowed down by another external force that is being applied to the car. More than one force was being applied, including gravity, static friction, and fluid friction.
Newton's Second Law:
The Second Law of Motion states that force equals mass times acceleration, or f=ma. Let's say you have a really tiny book, maybe 50 pages in length, and you have a huge encyclopedia, ranging anywhere from 700 to 800 pages. It takes less force for the tiny book to move at the same acceleration rate as the encyclopedia because the encyclopedia has a bigger mass. Therefore, the smaller something is, the less force it takes for it to accelerate. This means that the amount of force depends on the amount of mass the car has and the amount it accelerates. This law has to do with the water bottle rockets because the amount of acceleration that was applied to the rocket depended on the amount of water that was put into the rocket and how big or small the rocket was. To ensure that our rocket would go really high, we tried to make our rocket as light as possible and to add lots of water. We put 1000 milliliters into our rocket, which is a lot of force. In favor, our rocket accelerated a great amount because our rocket did not have a huge amount of mass, but had a lot of force.
Newton's Third Law:
Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. No, Newton was not talking about when you do something wrong and your mom punishes you. Think of it this way: if you're on a diving board, and you want to jump into the pool, you jump and push off against the diving board. I know it is hard to wrap your head around, but the diving board actually pushed back against you. Crazy, right? Another way to think about it is if you're in a row boat. When you row, you push the paddle against the water. In return, your boat moves forwards or backwards. This law is applied to the rocket because the compressed water pushes against the ground when launched. In return, the ground pushes against the water, which exerts the rocket high into the air.
Sliding Friction:
Sliding friction is the type of friction when something is resisting to the slide. Think of a skater ice skating. When the skater skates, are they more likely to go faster when they're skating on a really smooth surface, or on a really bumpy surface? Obviously, a skater wants the smooth surface because there is less sliding friction. The smoother a surface is, the less sliding friction there will be. Sliding friction applies to the parachute of the rocket. When the parachute deploys, it slides against the insides of the body of the rocket. To ensure that the rocket will come out really easily, the insides had to be as smooth as possible. They couldn't have random pieces of duct tape and the bottle could not be bent. Sliding friction also comes into play when the rocket comes off of the launcher. As the rocket comes off the launcher, the mouth of the bottle slides against the mouth of the launcher.
Fluid Friction:
Fluid friction has to do with anything that is moving through a liquid or gas. While moving through a liquid or gas, the water and air particles hit against the object, causing it to slow down. Think about when you're swimming, and when you stand in the shallow end of the pool and try to walk through the water. It is more of a tedious and longer task to walk through water than if you weren't walking in water. This is because water particles are hitting against your body and resisting you from moving faster. This has to do with our water bottle rocket because the rocket moves through the air after it is launched. In order for our rocket to be effected as little as possible by fluid friction, we used a nose cone so that the air would hit our rocket with minimum force.
Gravity:
When most people think of gravity, they think of it as this invisible force that pushes objects, including us, around. But, in reality, Gravity does not push things around. Instead, it is the element that pulls objects of a smaller mass to objects of a greater mass. The most common example that can be though of actually involves you. You see, everyone and everything here, on this planet, is currently being pulled toward Earth. If you hadn't already figured it out, our planet is HUGE, and you're just a measly hundred to two-hundred poundish body of mass. GRAVITY is the force that keeps your feet planted on the ground. Also, if you're wondering, the Earth is being pulled by the sun's gravitational force, so we are able to spin around the sun and be happy and alive and whatnot. Gravity can be applied to this project because gravity is the force that pulls the rocket back down towards earth after it is launched. Free fall would be the body of the rocket coming down from the air. But, because we wanted our rocket to stay in the air as long as possible, we used a parachute.