Our Actual Rocket
![Picture](/uploads/1/4/0/7/14075844/1369229748.png)
For this project, we made a water bottle rocket. This was definitely the hardest project out of the three and required the most work. At first, we thought we were going to make a rocket with a parachute, but we ended up making a backslider. A backslider is rocket without a parachute whose goal is to slow its descent by turning on its side and spinning. Only one other group made a backslider.
We used an ogive nosecone, which is a combination a conical and parabola nosecone. The ogive shape has more drag than the parabola shape, but less drag than the conical nose cone. This allows it to have some resistance, but not be held back by this resistance. We ended up using two large fins (not seen in picture) with small black fins instead of three small fins because they covered more surface area and were sturdier than the three small ones.
We ended up getting fourth place in the first tier.
We used an ogive nosecone, which is a combination a conical and parabola nosecone. The ogive shape has more drag than the parabola shape, but less drag than the conical nose cone. This allows it to have some resistance, but not be held back by this resistance. We ended up using two large fins (not seen in picture) with small black fins instead of three small fins because they covered more surface area and were sturdier than the three small ones.
We ended up getting fourth place in the first tier.
![](http://www.weebly.com/weebly/images/file_icons/mov.png)
Testing the Parachute #1 | |
File Size: | 9 kb |
File Type: | mov |
![](http://www.weebly.com/weebly/images/file_icons/mov.png)
Testing the Parachute #2 | |
File Size: | 7 kb |
File Type: | mov |
Data Table
Principles Covered
F = MA is very important here because how much force our rocket will have (and therefore how long it will stay in the air) is dependent on its mass since we will all be using the same amount of pressure, or acceleration. This ended up being even more important with our rocket because the faster it accelerated, the higher it would go and the longer it would last in the air. The amount of water we put into our rocket also came into play with our force because it increased the mass of the rocket, allowing it to have more force, but it would also require more acceleration.
Sliding and static friction go hand in hand. Perhaps one of the best examples to demonstrate this is when you are walking up a steep incline or hill. You want to have static friction because if you did not, you would not have any grip and just fall down the hill. When we were using the pressurizer to launch the rocket, we wanted static friction to help keep the rocket in place and not fall off the stand, but at the same time we didn't want the rocket to get stuck and not launch. Since we had a backslider rocket, it was all the more important that the rocket had sliding friction so that it would smoothly launch off launching platform.
Gravity played a huge part in this project. It was the force pulling the rocket back down to Earth; the very force we were working against the most. Other people with rockets used parachutes to combat this, but since we had a backslider, we had to use surface area and friction to combat it. Obviously, this didn't work as well as the parachutes, but it still managed to stay up in the air for a few seconds.
Inertia is "an object in motion will stay in motion and an object at rest will stay at rest until acted upon by outside, unbalanced force." Our rocket remained at its resting state until we launched it, allowing it to be affected by fluid friction and sliding friction. However, one could argue that it was out of its "unaffected, resting" state even before it launched because of static friction. Either way, the reason our rocket did not just keep going was because it was being affected by all kinds of unbalanced forces (gravity, friction, sliding friction, fluid friction, etc.).
Action/Reaction, or Newton's Third Law, was involved in the actual launch of the rocket. When the pressurized water was released out of the rocket, it pushed against the ground. Newton's Third Law says that "for every action, there must be an equal and opposite reaction". So, when the water pushed downwards (against the ground), it gave off an opposite and equal reaction, pushing the rocket up into the air with the same force.
Fluid friction was involved during the flight of the rocket. It was the friction in the air that we were working against during the launch; when the rocket is on its ascent, you want the least amount of fluid friction possible so that it accelerates as much as it can. However, on the descent, you want some fluid friction so that it doesn't just plummet to the ground.
Sliding and static friction go hand in hand. Perhaps one of the best examples to demonstrate this is when you are walking up a steep incline or hill. You want to have static friction because if you did not, you would not have any grip and just fall down the hill. When we were using the pressurizer to launch the rocket, we wanted static friction to help keep the rocket in place and not fall off the stand, but at the same time we didn't want the rocket to get stuck and not launch. Since we had a backslider rocket, it was all the more important that the rocket had sliding friction so that it would smoothly launch off launching platform.
Gravity played a huge part in this project. It was the force pulling the rocket back down to Earth; the very force we were working against the most. Other people with rockets used parachutes to combat this, but since we had a backslider, we had to use surface area and friction to combat it. Obviously, this didn't work as well as the parachutes, but it still managed to stay up in the air for a few seconds.
Inertia is "an object in motion will stay in motion and an object at rest will stay at rest until acted upon by outside, unbalanced force." Our rocket remained at its resting state until we launched it, allowing it to be affected by fluid friction and sliding friction. However, one could argue that it was out of its "unaffected, resting" state even before it launched because of static friction. Either way, the reason our rocket did not just keep going was because it was being affected by all kinds of unbalanced forces (gravity, friction, sliding friction, fluid friction, etc.).
Action/Reaction, or Newton's Third Law, was involved in the actual launch of the rocket. When the pressurized water was released out of the rocket, it pushed against the ground. Newton's Third Law says that "for every action, there must be an equal and opposite reaction". So, when the water pushed downwards (against the ground), it gave off an opposite and equal reaction, pushing the rocket up into the air with the same force.
Fluid friction was involved during the flight of the rocket. It was the friction in the air that we were working against during the launch; when the rocket is on its ascent, you want the least amount of fluid friction possible so that it accelerates as much as it can. However, on the descent, you want some fluid friction so that it doesn't just plummet to the ground.