Soft drink bottle using compressed air for thrust to act like a rocket.

[Jessielowe123]

Hey! This is the first time I have used this forum so I hope it all goes well and I am sorry if I break any rules on my first attempt.

I have been given a question which I believe will involve quite a lot of work, so I thought I would get some suggestions as to where I need to start.

Basically, I have to use a a soft drink bottle as a rocket and determine the range ignoring drag. I have been given:

Bottle Capacity: 1.25 L
Bottle Mass: 50 grams (0.050kg)
Outlet Diameter: 22 mm (0.022m) (Can be reduced to improve performance)
Compressed air
pressure inside bottle: 654 kPa (absolute)

This is purely theory it is not a practical task.

I have then been provided with Bernoulli's Equation:

$$\rho$$gh + 0.5$$\rho$$V^2 = constant

Where p = density, g = 9.81m/s^2, h = height, V = velosity, P = Pressure

I know I will eventually need to incorporate projectile motion equations, Ideal Gas Law and mass flows to find the range. Is there anywhere you can suggest I start as I do not want to go down the wrong path through hours of frustrating equations if it is the wrong way. I just do not know what equation flows onto the next and where to even start.

 

[Jhero]

Hello there! It's great to see you using this forum for the first time and I'm happy to help you with your question. I have some suggestions for you on where to start with this problem.

Firstly, it's important to understand the basic principles involved in this experiment. You will be using a compressed gas (in this case, air) to propel the bottle forward. This is similar to how a rocket works, where the combustion of fuel produces a high-pressure gas that is expelled out of the nozzle, creating thrust.

Next, you will need to understand the concept of Bernoulli's equation. This equation describes the relationship between pressure, velocity, and height in a fluid. In this case, the fluid is the compressed air inside the bottle. You can use this equation to calculate the velocity of the air as it exits the bottle.

Once you have calculated the velocity of the air, you can use projectile motion equations to determine the range of the bottle. This will involve taking into account the initial velocity, angle of launch, and the effects of gravity. You can also consider adjusting the outlet diameter of the bottle to see how it affects the range.

In addition, you mentioned the Ideal Gas Law, which relates the pressure, volume, and temperature of a gas. This could also be useful in your calculations, as it can help you determine the amount of air inside the bottle.

My suggestion would be to break down the problem into smaller, manageable steps. Start by understanding the basic principles and equations involved, and then gradually incorporate them into your calculations. You can also do some research and look for similar experiments or studies that have been done in the past, which may give you some insight on the best approach to take.

I hope this helps and good luck with your project! Don't hesitate to ask for further clarification or assistance if needed.