Rocket Definition and 1000 Threads

Homework Statement I want to try to derive the rocket equation and then add additional effects like gravity, air resistance, etc. Here's the equation that I found online: Homework Equations p (momentum) = mass * velocity F (force) = Δp / Δt The Attempt at a Solution [/B] pi = mv Here is...

Hey, I'm tutor for theoretical physics for first year students and I found a question that I couldn't answer so far. It's about the rocket equation. I tried to derive the acceleration without using infinite small variables, but somehow there is one term left that shouldn't be there. In the...

I recently thought about getting it as a tattoo, and thought I'd learn a little more since you know, I might be tattooing it on me lol and I really haven't done much research other than a couple first page Google results so far. I figured this would be a good place to start and learn some...

Hi,does anyone know how many sensors a typical rocket have and what they are? Where can I find such a list?Senmeis

Homework Statement Find the initial velocity of the boost phase (when water is coming out). Here is everything I know - Mass of rocket with no water is 0.13kg, mass of rocket with water is 1.1kg. The total length of the rocket is 0.48m. The time to the maximum point is 3.46 seconds, and total...

Hi! I'm trying to analyse how aerodynamics affect a rockets movement, I am having a bit of trouble though. Any tips on how i would start out or look? The method is supposed to include differential equations which i am familiar with but have a bit of trouble tieing it all together. Where do i...

So I'll soon be writing an assigntment on the physics and chemistry behind firework rockets and that's why I'm here! I've already prepared for the chemistry part but when it comes to the physics part then I am a bit lost. Bare in mind that I'm supposed to learn something new (myself) and explain...

Homework Statement A rocket burns out at an altitude h above the Earth's surface. Its speed v0 at burnout exceeds the escape speed vesc appropriate to the burnout altitude. Show that the speed v of the rocket very far from the Earth is given by v=(v02-v2esc)1/2 Homework Equations KEf-KEi=Ui-Uf...

I am referring specifically to chapter 3.2 in John Taylor's textbook Classical Mechanics where he develops the equation of motion for a rocket, but not in enough detail for me. Taylor first writes down the change in the momentum of the rocket as dP = P(t + dt) - P(t) = (m + dm)(v + dv) - mv =...

Homework Statement [/B] The total mass of a space shuttle and its launch vehicle is M=2000t. a) What must be the minimum size of the thrust force, to make the rocket move? b) The actual thrust of the rocket is F=30MN. What is its acceleration in the beginning? c) Assume that a mass of a...

Homework Statement A rocket, total mass 1.00 × 10^4 kg, is launched vertically; eighty per cent of the mass being fuel. At ignition, time t = 0, the thrust equals the weight of the rocket. The ejected exhaust gases have a speed of 9.00 × 10^2 ms ^–1. Assuming the rate of fuel consumption and...

So if you have a rocket let's say that discards all the structural and engine mass continuously at zero velocity that is relative to the rocket until only the payload is traveling at the final velocity - then what will the equation of motion will look like? we can neglect the drag and...

Hi there, Recently i was watching some rocket launches and was wondering why they are tethered before takeoff, after some searching i found out that they are used to keep a constant supply of fuel to replace the part that boils off. But is there any other uses for such tethers?

Homework Statement A 50.0 kg rocket is launched straight up (we’ll call this the y direction). Its motor produces constant acceleration for 10.5 seconds and stops. At the time of 12.5 seconds the altitude of this rocket is 333 m. (ignore air resistance and take g=9.80m/s^2) a. What is 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 1.50 m/s2 until its engines stop at an altitude of 110 m. (a) What is the maximum height reached by the rocket? (b) How long after lift-off...

Homework Statement A patrol boat off a coast is ordered to destroy a rocket launcher that sits on the roof of 40-meter tall building. The horizontal distance between the boat and the rocket launcher is 1500 meters. The muzzle velocity of the patrol boat’s stabilized 30-mm cannon is 141...

I read that a thrust augmentor can significantly increase the efficiency of a jet engine (http://www.pulse-jets.com/phpbb3/viewtopic.php?t=931). Now from my understanding, the thrust agumentor is sort of like a ramjet. Only, in this case, the cold air is being sucked in along with the hot air...

Homework Statement A Rocket with an engine that causes a net acceleration of 4m/s^2 launches with an initial velocity of 20m/s. The engine fuel lasts for 0.8s. A secondary engine then fires causing a net acceleration of 2m/s^2 for 0.6s How far off the ground is the rocket when the secondary...

Hi. In Newtonian physics, total mass is conserved, but open systems can obviously gain or lose mass, such as a rocket. But how can the term ##\dot{m}v## be Galilean invariant?

Homework Statement A rocket moving with speed v passes a stationary observer. The observer waits a time T (according to his clock) after the rocket passes and send a pulse of light in the direction of the rocket. The rocket pilot notes that, according to her clocks, the time elapsed between the...

I just look at a rocket leaving his lunch pad. Vapor condensate spin around the rocket. at 0:40

I have this exercise which I don't understand its solution. I am attaching both the exercise and its solution. It's problem 2: rocket trip. What I don't understand in the solution they write that: "and from this you get: $$\omega < \frac{1}{R}\sqrt{1-2m/R}$$ Then plug in ##\omega = m/R^3## to...

Hello everybody, I hope you are doing fine. I'm currently designing an injector for a hydrogen peroxide - ethanol engine, and the following formula is confusing me: Q = Cd * A * sqrt( 2 * dP / rho); where Cd is the discharge coefficient, A the total area, dP the pressure drop, and rho the...

Looking at a humble smoke detector - a metal plate with some alpha source on one side. I guess the fission products / apha etc emitted in one direction are absorbed into the metal, and the opposite direction go into space. So there should be a minute net force ? Would that be useful as a "sail"...

Is the pressure due to the hot gas exhaust stream on the inside walls of a rocket motor bell nozzle positive or negative? Does the rocket exhaust exert a outward pressure on the nozzle walls due to the sheer volume of the exhaust gases or is the pressure a negative one due to the exhaust stream...

Why is it that variable geometry nozzles, like those found on jet engine(iris nozzles), are not used as rocket nozzle to provide better altitude compensation?

I stumbled upon a 3-year old article from Wired that poses this question on rockets: Suppose I have two rockets with a mass M and fuel mass m. Rocket A shoots all the fuel at once (again, like a nuclear propulsion engine) with a fuel speed of u and rocket B shoots two blobs of fuel—first a shot...

In this derivation of the Ideal Rocket Equation (https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation#Most_popular_derivation), they use the fact that ##V_e = V - v_e##, or that the velocity of the exhaust in the observer frame ##V_e## is the velocity of the rocket ##V## minus the speed of...

Homework Statement Homework EquationsThe Attempt at a Solution 19800*.35 = 6930J

Hi, When considering the drag coefficient of a rocket in transonic/supersonic flight, I always expected the drag coefficient to peak at exactly Mach 1 due to the abrupt increase in pressure that occurs when breaking the sound barrier. However, I have been looking at several websites and...

My 12 year old asked me this question. I have a MS in Mechanical Engineering, so I can usually answer his physics questions, but this one stumped me. When lifting off, why do most rockets turn close to horizontal almost immediately? Of course we know they need mostly horizontal speed to...

Homework Statement Consider a rocket subject to a linear resistive force, $$f = -bv$$, but no other external forces. Use Equation (3.29) in Problem 3.11 to show that if the rocket starts from rest and ejects mass at a constant rate $$k = -\dot{m}$$, then its speed is given by: $$v =...

I recall reading that in the context of special relativity, one will notice differences in the acceleration of an idealized born-rigid spaceship when one compares two identical spaceships, one with the rocket motor mounted in front, the other with the rocket motor mounted in the rear. I'm...

I try to calculate the speed curve of a relativistic rocket driven by a 100% efficient engine with constant thrust, when traveling to a distant star. All equations I can find consider constant acceleration, which of course is not working, since the ships mass decreases when the fuel is used...

Homework Statement A person whose mass is 20 kg needs to accelerate vertically from the surface of the Earth at 5.0m/s^2 and is trying to pick which rocket he should strap to his back. How much thrust does he need if each rocket has a mass of 30 kg? Homework Equations F=ma The Attempt at a...

Hi! There is this question in my practice exam: How many ways can all the letters in the word ROCKET be arranged so that the vowels are always together? The answer is 5! x 2. I understand where the 2 is coming from. What I don't understand is the 5. Shouldn't it be 4!, since we already...

http://www.businessinsider.com/how-vulcan-rocket-works-united-launch-alliance-2018-2

NASA decided to stop *WFIRST and concentrate on Mars project (send humans to Mars). What do you think about it? In my opinion, since a lot of ventures have begun space developments such as SpaceX and this proves that rockets make money, NASA should tackle WFIRST. Generally, we cannot earn...

Homework Statement A rocket (initial mass ##m_o##, constant exhaust velocity ##v_{ex}## needs to use its engines to hover stationary, just above the ground. a) If it can afford to burn no more than a mass ##\lambda m_o## of its fuel (##\lambda \lt##), for how long can it hover? b) If ##v_{ex} =...

I ran into this problem and need some guidance. Here's the question exactly as it appears in my sheet: "A 500 kg rocket is set for vertical take-off. If the exhaust speed is 1,000 m/s, the mass of gas ejected per second to supply the thrust needed to overcome the weight of the rocket is:"...

Homework Statement The Earth has a mass of 5.98 x 1024 kg and the moon has a mass of 7.35 x 1022 kg. The distance from the centre of the moon to the centre of the Earth is 3.84 x 108 m. A rocket with a total mass of 1200 kg is 3.0 x 108 m from the centre of the Earth and directly in between the...

Hi, I am currently working on a Hybrid Rocket which uses fuel grain as 3-D printed ABS and oxidizer as N2O, but i need to calculate some basic parts such as required thrust to reach specific altitude. I want to calculate the required thrust to reach 1.5km for 10kg rocket with 7cm radius. It will...

Homework Statement A cylindrical rocket of diameter 2R and mass M is coasting through empty space with speed v0 when it encounters an interstellar cloud. The number density of particles in the cloud is N particles/m^3. Each particle has mass m << M, and they are initially at rest. Assume each...

Hi, I am looking into aerodynamic parameters for rockets (ogive nose, cylindrical body of different diameters, four fins at bottom) and have a question about the lift coefficient. If a rocket is launched vertically, with zero incidence angle and wind, would that result in a very small lift...

Hey I'm new to Physics. I have a question. Is it possible to use the force generated when air entera a vacuum tube to launch something into space? Can anybody throw some light on this in simple words please. Thank You.

Rockets are quite expensive and it takes about 2000 to 10000 dollars to place 1 pound into orbit. So I was wondering: Is the size or the fuel mass of a rocket a big concern or will it be of no help economically if we make smaller rockets with less fuel mass for the same amount of payload...

This is an IB problem from November 2017. Two rockets are separated by 6E8m (2 sec x c, or two light-seconds), w.r.t. Earth, and are approaching Earth from opposite directions. Rocket A approaches from left at 0.6c. Rocket B approaches form right at 0.4c. According to Earth, when do they...

$\tiny{UP 2.1}$ $\textsf{A rocket carrying a satellite is accelerating straight up from the Earth's surface}$ $\textsf{At 1.15 after liftoff, the rocket clears the top of its launch platform, 63m above the ground.}$ $\textsf{After an additional 4.75s it is 1.00km above the ground.}$...

So we have: stability for n < 1 instability for n > 1 I assume to get the time growth, I have to integrate the above first eqn. However I also get ln(δpc) at the LHS from the integrating. However the above equation for time growth removed that ln(δpc) and thus I can't...

I'd always thought that to find the mass ratio of a given rocket, one simply had to divide the rocket's wet mass (i.e. fuel and propellant) from its total mass. An example: a rocket's total mass = 2,000 tonnes: its wet mass = 1,000 tonnes. Answer: 2. Is this correct? (I'm pretty sure it isn't...