Rocket Definition and 1000 Threads

Let’s consider Galileo’s description of relativity of motion using the example of a moving ship. The ship is at rest and made to accelerate extremely slowly for a few minutes, and then moves at a constant velocity. When the ship is moving at some constant velocity, the contents of the ship will...

Suppose a rocket is hovering above the moon at a constant height, burning just enough propellant to stay at that height, and not move upwards or downwards. Viewed from an inertial frame, we have. Initial energy (just before ignition) : 1. Gravitational potential energy between rocket and...

I've been thinking. Would it be any more efficient to use the angular momentum of a spinning rocket engine nozzle to eject the rocket fuel? Just an idea. Post any questions below

Homework Statement So you're shooting off a water rocket, which has some water inside a 2L soda pop bottle. You're then pumping (for example, a bicycle pump) to compress more and more air inside to a higher pressure. Homework Equations Well, work = F*d. If you measure the stroke of the...

Homework Statement A model rocket is launched straight upward with an initial speed of 50.0 m/s. It accelerates with a constant upward acceleration of 2.00 m/s^2 until its engines stop at an altitude of 150 m. How long after lift off does the rocket reach the maximum height? from...

I'm currently working on a bottle rocket for my physics class. Instead of taking the assigned experiment, a friend and I have chosen a side experiment to work on. The experiment: Create a rocket using a 2L bottle as a compression chamber and compare the time required to reach the apex of its...

Hello Everyone, If I were to blast off my model rocket from a weather balloon what altitude would it reach? I have a model rocket that routinely reaches 10,000' @ sea level. If this were attached to a weather balloon and launched at 100,000', what would happen? Are gravitational pull...

I started taking MIT's online physics course a couple of days ago, and since I have no physics background at all, I'm getting a bit confused with dimensional analysis. I'm trying to find a formula for the terminal velocity of a rocket, using air density ρ, gravity g, area of rocket affected by...

Bottle Rocket Fuels (URGENT) Assuming the same volume, which should travel higher - a bottle filled with a dense fluid or a bottle filled with a less dense fluid? Thanks for reading!

Suppose I am building a rocket for interstellar travel. I want it to be able to go as fast as possible for a given fuel load. Since the momentum of my rocket will equal the momentum of the fuel I eject from the back of it, it behooves me to eject the fuel with as high a velocity as possible...

Hi everyone, My high school class is doing a competition where we have to build a rocket out of a 2L pop bottle powered by compressed CO2 and launch it (not directly up but at an angle) we need to... -achieve maximum distance -have minimimal horizontal deviation -protect an egg that the...

I am building a water rocket for my physics class and I want to make my calculations as precise as possible. I want to calculate throttle, velocity, acceleration, momentum, and max height. With that said, what should I take into account? Gravity, wind velocity, shape of cone of the rocket...

Homework Statement So we launched small rockets on our last day, but have a week to turn in the homework based on the launch, but seeing as we aren't allowed back in school I can't ask questions I am lost. We haven't dealt with anything remotely related to trajectory since the beginning of...

A livestream video feed from the event has started and can be accessed via the CS homepage [1] or the corresponding blog on Wired [2]. Some background information about CS can be found on [3] together with a (very) short description on the TM65 [4]. [1] http://www.copenhagensuborbitals.com/ [2]...

When I was at Uni, in the 60s, we had a brief course on 'Space Physics'. It had a hotch potch of topics in it and one of them was about actually launching satellites. 'In those days', apparently, vehicles were rotated during the launch and this rotation had to be eliminated once they were in...

Hey, I have a question on a rocket in deep space (all external forces negligible), basically I'm doing something wrong the latter part of the question - maximizing the momentum via differentiation, here's the question: So the momentum at a given mass 'm' is ...

Homework Statement Rocket motors make a rocket of mass of 2200kg accelerate at 2.5m/s^2 over a distance of 650m in deep space. What is the work done? The Attempt at a Solution F=m*a 2200kg*2.5m/s^2 = 5500N 5500*650= 3575000 When I look at the answer page it tells me the force...

I worked through a simple twin paradox problem, and I think I have the correct solution. However, I wanted to confirm that my numbers are correct. There is nothing fancy about the solution, but it resolves the "paradox" completely for me. Every other resolution I have looked at either leaves...

Suppose we have a satellite in an elliptical orbit around the Earth with the major axis pointed towards some fixed point in the heavens. What is the minimum number of rocket burns so that the major axis is rotated 90 degrees and the final and initial energy are the same. Is the number 2? At...

Because this is not a 'formal' question I won't use the template. I was wondering, what if I have a rocket (varying mass) with air resistance acting upon it? Let's say the F=-kv u is the speed of the rocket relative to the gas, and the rate of mass/second extracted is b without g it would...

If a rocket is traveling past the Earth at speed v, and the time interval measured by the astronaut is four times smaller than the time interval measured by an observer on the Earth. What is the value of v I have attempted the solution and got: Δt=γΔt' Where i believe that gamma will be...

Mythbusters did a test to see if a water heater would shoot through the roof of a two story building (home). They close all orfices, heated the water and it soared through the roof. They computed the final pressure as 85,000 pounds. As I recall they computed this by multiplying the area of the...

Homework Statement A rocket passes the Earth at 0.8c. As it goes by, it launches a projectile at 0.6c perpendicular to the direction of motion. What is the projectile's speed in the Earth's reference frame? Homework Equations [;u=\frac{u'+v}{1+u'v/{c}^{2}};] The Attempt at a Solution Since...

So I have been thinking and there's probably a good reason why it doesn't exist already but i'll go ahead and share my idea here on the forums. How about making something similar to the hadron collider but the tube that runs underground is capable of housing the space shuttle. It sits on rail...

Alright everybody, I REALLY need help on this and I only have a limited time. So I took a video of a model rocket and using the video analysis software, Tracker, I have a graph of position vs. time. Now I don't know calculus yet (only in pre-calc as of now), so the derivation of the graph won't...

Hello Forum, Let us review about rocket move.The Rocket moving with 2 mechanical principe;Newton's 3 and conservation of momentum.If rocket at t=0 is in rest condition (E=0),after the gas with dm mass go out to the back from rocket ,then rocket move to the front(E=Ek1+Ek2). Nothing external...

I am doing an assignment about launching a rocket and at the moment I am looking for the delta V of the rocket. I have done a few researches and i found a method of finding the energy of the rocket and find the delta vee of it , but then i found this article and I am not sure if it is delta vee...

So, I need to make an Excel spreadsheet that realistically models the motion of a toy rocket. I need to take drag, gravity, and thrust into account, keeping in mind that the latter two will be influenced by the change in mass. The equation for force I must use, then, is: F = ma + v(dm/dt)...

Homework Statement A warlock testing a rocket broom takes off from a standing start and flies at fixed elevation. The warlock and fueled rocket system start out with mass Mi. The rocket fires with exhaust speed u, losing mass at a constant rate R, and we’ll assume air drag is negligible. If...

When a rocket is launched, it starts not with velocity zero, but with the rotation velocity which the Earth gives it. Thus if a rocket is launched eastward, it requires a smaller boost (and if westward, a larger one) to achieve orbit. with a latitude of 31.1 degrees, cos(31degrees) 24902/24 =...

Homework Statement A 10.1 kg weather rocket generates a thrust of 193.0 N. The rocket, pointing upward, is clamped to the top of a vertical spring. The bottom of the spring, whose spring constant is 415.0 N/m, is anchored to the ground. (a) Initially, before the engine is ignited, the rocket...

Homework Statement Do rockets have linear or exponential acceleration? The Attempt at a Solution This is not a homework question I was just wondering if Rockets have linear or exponential acceleration. I was thinking that they have exponential acceleration because of the constant loss of mass...

Homework Statement A rocket is launched vertically up with no initial velocity. Propulsion is provided by the ejection of mass with constant velocity of ejection u = 66.0 m/s relative to the rocket and at a constant rate so determined that the initial acceleration is zero. The mass of fuel...

Hi everyone, Quick question I may just not be thinking right here but I was trying to find the acceleration, velocity, and position of a rocket as a function of time. I started with acceleration: a =\frac{T}{m-\dot{m}t} - g where T is the Thrust, m is the initial mass, mdot is the mass flow...

Homework Statement The pilot of a rocket wants to reach a star in 1 year. The rocket is currently on Earth. The star is 4 light years away, measured from an observer on Earth. What velocity is needed for the pilot to reach the star in a year in the pilot's/rocket's time? Homework Equations...

Homework Statement I a little lost on how to use the relativistic velocity addition formula to determine the increase in speed "v" over a short time interval in the Earths frame of reference, for a rocket having left Earth at rest and traveling through space accelerating at constant acc. of...

I know I've done this problem a few times before but I'm just a fumbling idiot at the moment.. Homework Statement Rocket has an acceleration of 12m/s^2 and at an altitude of 1km the motor shuts off. What is the maximum height? Homework Equations V^2=V_i+2a(x_f-X_i)...

Homework Statement Consider a rocket is subject to linear resistive force, f = -bv . \dot m is constant. Use the equation: m \dot{v} = -\dot{m }v + f to determine the velocity of the rocket : since the rate of mass lost is constant let \dot{m} =k vex = nuzzle velocity v = \frac{k}{b}...

Hi all, Does anyone know where I can find the formula for the relavistic rocket equation? That is, I want to know the mass of fuel required to accelerate a rocket from 0 to β, for a given acceleration A, assuming the rocket (with no fuel) has a mass of M. All of this would be in the frame of...

Homework Statement Find the speed v of the rocket when the mass of the rocket = m. The rocket starts from rest at with mass M. Fuel is ejected at speed u relative to the rocket. Homework Equations m1v1 = m2v2 The Attempt at a Solution In the textbook, it starts off with a moving...

I'm modelling a rocket leaving to outer space and I want to incorporate air resistance in the model. I however have no clue what the drag coefficient as well as the cross sectional area of a typical rocket would be. Can someone help me on this?

Hi, I'm wanting to do a fun numeracy exercise for my students. I'm planning to have them construct bottle rockets, take measurements and then calculate/graph how high their rockets get using simple triangulation. From that, I was hoping to get them to calculate what the thrust was of their...

Because torque is force times distance, wouldn't it only take a relatively small force to make a rocket unstable if the force was applied near the base or the top? How is it kept stable? I just saw SpaceX's future plans to make a fully recyclable launch vehicle; I think it is far fetched TBH.

Homework Statement A rocket accelerates upwards from the ground at 25ms-2 for 2.5 s at an angle of 80 degrees to the horizontal. The rocket motor then stops and eventually falls to the ground. Neglecting air reststance and assuming thet the trajectory during acceleration is a straight...

Did a question about this a few weeks ago, but I thought I might do another, as I don't quite get, what is going on. The relationship: v=vex * log(m0/m(t)) tells us that a rocket will attain greater and greater acceleration as time goes. However, when I try to simulate this in Matlab I get...

Hi, I have this particular question, to which i think my method is correct, though the answer from the book which this question is in gives different to mine. Please! any assistance will be very much appreciated! Question: A Rocket was launched directly upwards from rest. Its motors...

Look at the attached picture, which is taken from my textbook. I don't understand the equation: v = vex * ln(m0/m(t)) If the rocket looses mass at a constant rate, wouldn't that equation then say, that the acceleration decreases as time goes. Since the curve of ln(>1) flattens out. That...

I'm reading Spivak's mechanics book and I'm stumped on some of the math in his derivation of an analytic expression for the motion of a rocket in empty space. Let \mathbf{v}(t) be the rockets velocity, let \mathbf{q}(t) be the velocity at which fuel is ejected from the rocket, and let m(t) be...

Fission-fragment rocket The wiki entry seems to paint this system in a positive light, so is it a workable propulsion system for high speed space missions? How long would a trip to Pluto take with something like this? How many years away is this from becoming a reality?

Homework Statement We have some data for a rocket test, and I have plotted thrust against time. To find the total impluse, we were told to find the area under the thrust graph. But I am a little confused about something. I defined my zero time as the time the thrust started to increase, but...