two stage rocket physics problem

Best study tips and tricks for your exams. Net Force (and Acceleration) Ranking Tasks, Trajectory - Horizontally Launched Projectiles, Which One Doesn't Belong? Obviously a two-stage rocket is a perfect vehicle to LEO. The second factor is the rate at which mass is ejected from the rocket. For a Space Shuttle launch, 3 g's are the designed limit of acceleration. Acceleration of a rocket is. The equation is given as: v = v e l n m 0 m f = I s p g 0 l n m 0 m f. Where, v: maximum change of velocity of the vehicle. Not finding what you wanted? Then, it ejects one unit of fuel at a high speed (the exhaust velocity) causing the rocket and the remaining unit of fuel to gain a little velocity. Reproduction of material from this website without written permission is strictly prohibited. By using this website, you agree to our use of cookies. Consider the direction of motion of the rocket before the explosion to be the positive direction, i.e., direction away from the Earth to be positive. The total height of the rocket at launch was 110.6 m; it had a total mass of 2.97million kg, and could take a payload of 140000 kg to low-Earth orbit or a payload of 48600 kg to the moon. (b) How much energy was supplied by the explosion? The mathematical analysis involves the calculations of slopes and areas for the two fuel stages and the free-fall stage that follows. Since the magnitude of both \({v_{\rm{A}}}\) and \({v_{\rm{B}}}\) is positive, the direction of both the fragments is away from the Earth. This saves energy because the depleted first stage is not carried all the way into orbit, allowing the second stage to travel farther with less fuel. Calculate the velocity of the boat immediately after, assuming it was initially at rest. After ten seconds, the second fuel stage ends and the rocket is acted upon only by the force of gravity. The three rocket stages are separated by rings around the engine of the next stage. The Rocket Lab Rutherford engines, designed for small orbital rockets like the Electron, use pumps powered by lithium-ion batteries. Clicking/tapping the hot spot opens the Interactive in full-screen mode. Two Stage Rocket. 1.7 Solving Problems in Physics. It takes an enormous amount of energy (and therefore, fuel and money) to send a payload into space. There is a small hot spot in the top-left corner. This continues until a time t 1. We use cookies and those of third party providers to deliver the best possible web experience and to compile statistics. The reason it works is explained by the physical make-up of the rocket motors. Figure 8.12 (a) This rocket has a mass m and an upward velocity v. Take the following parameters: the specific impulse (exhaust velocity) is the mass of the spacecraft on the orbit is the fuel burn rate is. The first will fire for a time, getting the rocket up part ways. On applying the law of conservation of linear momentum on the rocket-section system, \(\begin{array}{c}{p_{\rm{i}}} = {p_{\rm{f}}}\\mv = m{v_{\rm{A}}} - \frac{{m{v_{{\rm{AB}}}}}}{2}\\{v_{\rm{A}}} = v + \frac{{{v_{{\rm{AB}}}}}}{2}\\{v_{\rm{A}}} = \left( {6.60 \times {{10}^3}\;{\rm{m/s}}} \right) + \frac{{\left( {2.80 \times {{10}^3}\;{\rm{m/s}}} \right)}}{2}\\ = 8.00 \times {10^3}\;{\rm{m/s}}\end{array}\). Instructors are permitted to make and distribute copies for their classes. On substituting the given values in the above expression, \(\begin{array}{c}\Delta KE = \frac{1}{4}m\left( {v_{\rm{A}}^{\rm{2}} + v_{\rm{B}}^{\rm{2}}} \right) - \frac{1}{2}m{v^2}\\ = \frac{1}{2}\left( {725\;{\rm{kg}}} \right)\left[ {\left( {8.00 \times {{10}^3}\;{\rm{m/s}}} \right) + \left( {5.20 \times {{10}^3}\;{\rm{m/s}}} \right)} \right] - \frac{1}{2}\left( {725\;{\rm{kg}}} \right){\left( {6.60 \times {{10}^3}\;{\rm{m/s}}} \right)^2}\\ = 7.11 \times {10^8}\;{\rm{J}}\end{array}\). If the rocket of total mass 8M (say) had just one engine and it burned 7M of its fuel, it seems as if the same effect would be obtained as firing 3 identical rockets simultaneously. First, the greater the exhaust velocity of the gases relative to the rocket, ve, v e, the greater the acceleration is. (c) What will be the maximum height of each ball after the elastic collision? How many such bombs would have to explode simultaneously to release the destructive energy of the asteroid collision with the Earth? Two Stage Rocket. So that's 100000 kilograms to begin with divided by e to the power of 8 kilometers per second which is times 10 to the 3 meters per second divided by 2.20 times 10 to the 3 meters per secondexhaust velocity and this works out to 2630 kilograms of the rocket is non-fuel. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. The momentum of the rocket after the explosion is calculated as follows: \(\begin{array}{c}{p_{\rm{f}}} = {m_{\rm{A}}}{v_{\rm{A}}} + {m_{\rm{B}}}{v_{\rm{B}}}\\ = {m_{\rm{A}}}{v_{\rm{A}}} + {m_{\rm{B}}}\left( {{v_{\rm{A}}} - {v_{{\rm{AB}}}}} \right)\\ = {m_{\rm{A}}}{v_{\rm{A}}} + {m_{\rm{B}}}{v_{\rm{A}}} - {m_{\rm{B}}}{v_{{\rm{AB}}}}\\ = \left( {{m_{\rm{A}}} + {m_{\rm{B}}}} \right){v_{\rm{A}}} - {m_{\rm{B}}}{v_{{\rm{AB}}}}\\ = m{v_{\rm{A}}} - \frac{{m{v_{{\rm{AB}}}}}}{2}\end{array}\). You can find this page online at: https://www.sciencebuddies.org/teacher-resources/lesson-plans/two-stage-balloon-rocket. We use cookies to provide you with a great experience and to help our website run effectively. Right-clicking on the PDF above displays additional options. Problem 14. Consider an extremely simple toy model of a rocket. During the first part of the problem, the observed acceleration of the rocket was 27 m/s 2 and the rocket accelerated from zero to 86 m/s while traveling a distance of 140 m. Knowing these values at Point 2 allowed you to then learn about Point 3, with the understanding that the observed acceleration of the rocket between Points 2 and 3 was -9. . Note however, that from 10 to 16 seconds, the rocket continues moving upward (the velocity values are positive). Introduction. Then the first stage engine drops off revealing a second engine. The second stage is lit by the blowthough of the first stage into the nozzle of the second. As the rocket expels. This is why nearly all rockets into LEO have two stages. In direct staging, the lower "booster" stage motor ignites the top motor in the rocket. A rocket generates thrust using a controlled explosion as the fuel and . The stack has been certified (meaning tested to the point that we know it will keep working) to 3.3 g's. 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JavaScript is disabled. 2.1 Scalars and Vectors. This rocket carries the Apollo 15, the fourth mission to make it to the moon. The second factor is the rate at which mass is . For maximum power generation, should the turbine blades be designed so that the water is brought to a dead stop, or so that the water rebounds? From that instant, it begins to move upwards with a constant acceleration. The many worlds theory is a baroque solution to the unique problems of quantum mechanics and is simply not good science. The point of the exercise is to practice the calculation and be able to check the answer with the simulation. Let this explanation B A. (a) What is the speed and direction of each section (relative to Earth) after the explosion? This two stage rocket lab is based on a Conceptual Physics Lab by Paul Hewitt. Each time the velocity increases by one notch, the mass doubles. Right-clicking on the PDF above displays additional options. Speed of the rocket, \(v = 6.60 \times {10^3}\;{\rm{m/s}}\). The practical limit for ve v e is about 2.5 103 m/s 2.5 10 3 m/s for conventional (non-nuclear) hot-gas propulsion systems. The solution begins with. This is a high-school. The rocket equation ( 1) gives the speed change as. In a two-stage rocket launch, the first stage lifts the rocket through the initial phase of its flight. The second part is a verified and peer-reviewed physics model that simulates the rocket . There are two types of rocket staging, serial and parallel. A Multistage Rocket. A balloon is taped to a straw which rides along a piece of string. Students construct a "rocket" that will travel 4.0 m and then RETURN without intervention. The Physics Classroom Tutorial. Friction between the string and the straw acts opposite the direction of motion. We use cookies to provide you with a great experience and to help our website run effectively. On the graphs below, sketch qualitatively accurate (i.e., we don't care about the values but we do about the shape) graphs of each of the height of the rocket, y, its velocity, v, its acceleration, a, the force on the rocket that results from the firing of the engine, F, and the net force on the rocket, Fnet. An internal explosion breaks an object, initially at rest, into two pieces, one of which has 1.5 times the mass of the other. Net Force (and Acceleration) Ranking Tasks, Trajectory - Horizontally Launched Projectiles, Which One Doesn't Belong? Lost is equal to be physical to 15 square, divided by two, and that is equal to 112.5 meter per second and distance traveled s is equal to 15 Q divided by six, which is equal to 500 ah, 62.5 meter and be lost. Using the Interactive The Two Stage Rocket Interactive is shown in the iFrame below. A large fraction (typically 90%) of the mass of a rocket is propellant, thus it is important to consider the change in mass of the vehicle as it accelerates. The first stage is ignited at launch and burns through the powered ascent until its propellants are exhausted. It subsequently experiences a downward acceleration of -10 m/s/s. [Hint: What is the change in kinetic energy as a result of the explosion?]. Then, after its fuel is depleted, it breaks away and falls back to earth, while the second stage continues its flight. 2023 Physics Forums, All Rights Reserved, http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html, Two Stage Amplifier -- Find the Input Resistance, Torque on two pillars (introductory physics problem), Rocket problem -- separated fuel tank in free fall, Rocket Problem -- Solve using the Rocket Equation, Problem with two pulleys and three masses, Impact force of model rocket with parachute, Buoyant force acting on an inverted glass in water, Newton's Laws of motion -- Bicyclist pedaling up a slope, Which statement is true? According to Newton's third law of motion (for every action there is an equal and opposite reaction), this means the balloon is pushed forward along the string. Not only should we resist its strange appeal, it's time to find another way, writes Philip Ball. Resuming: - Closed system, don't loose mass: use F= dp/dpt = m*dv/dt + v*dm/dt. An exercise is provided to guide the activity for classroom use. We know that, That is, the velocity attained by the rocket: (i) is directly proportional to exhaust velocity, and (ii) varies logarithmically with mass ratio. Typical margins in structural design are 40%. Materials needed for a balloon rocket include: multiple balloons, an air pump, scissors, straws, fishing line, tape, a cardboard tube, and binder clips. A 725-kg two-stage rocket is traveling at a speed of \({\bf{6}}{\bf{.60 \times 1}}{{\bf{0}}^{\bf{3}}}\;{\bf{m/s}}\) away from Earth when a predesigned explosion separates the rocket into two sections of equal mass that then move with a speed of \({\bf{2}}{\bf{.80 \times 1}}{{\bf{0}}^{\bf{3}}}\;{\bf{m/s}}\)relative to each other along the original line of motion. First, the greater the exhaust velocity of the gases relative to the rocket, v e, the greater the acceleration is.The practical limit for v e is about 2.5 10 3 m/s for conventional (non-nuclear) hot-gas propulsion systems. This simple case of uniform staging enables us to calculate the ultimate rocket with an infinite number of stages. A child in a boat throws a 5.30-kg package out horizontally with a speed of 10.0 m/s Fig. It explains how to calculate the maximum height and total flight time of the rocket as well as the final. In the two fuel stages, the rocket experiences an upward acceleration of +10 m/s/s and +4.29 m/s/s respectively. . A good example of this is a balloon. They work based on a simple physics concept in which water is forced out the bottom of the rocket by air pressure, and in doing so exerts an upward force pushing up on the rocket (Newton's third law). v = ve * ln (m0 / mf) In which v stands for Change of Velocity. Net Force (and Acceleration) Ranking Tasks, Trajectory - Horizontally Launched Projectiles, Which One Doesn't Belong? A two-stage rocket accelerates from rest at +3.57 m/s/s for 6.82 seconds. Page last modified 1996-2022 The Physics Classroom, All rights reserved. It stores two units of fuel in its tanks, shown in red: A schematic diagram of a rocket's operation (image by author, CC BY 4.0.) In terms of relative velocity, the velocity of section B can be written as follows: \(\begin{array}{c}{v_{{\rm{AB}}}} = {v_{\rm{A}}} - {v_{\rm{B}}}\\{v_B} = {v_{\rm{A}}} - {v_{{\rm{AB}}}}\\\;\end{array}\) (i). In the first stage of a two-stage rocket, the rocket is fired from the launch pad starting from rest but with a constant acceleration of 3.50 m/s 2 upward. More powerful engines like the Merlin, RS-25, or F-1 engines use more complex combustion cycles that siphon off some of the combustion's energy to power the pumps. The software consists of three parts; the first part is a GUI that enables the user to design a rocket. - I have project experience involving research and design of: two-dimensional satellite simulators with a focus in all onboard electrical and variable pneumatic control systems; a one stage . Figure 14.2: Schematic for application of the momentum theorem. A two-stage rocket is traveling at 1200 m/s with respect to the earth when the first stage runs out of fuel. Take the positive direction as upward. It takes an enormous amount of energy (and therefore, fuel and money) to send a payload into space. Often, testing and analysis are only taken to 10% above the designed limit. Repeat the preceding problem but for a rocket that takes off from a space station, where there is no gravity other than the negligible gravity due to the space station. This lesson expands on the traditional activity by adding a second stage to the balloon rocket, modeled after how real rocket launches work (Figure 2). B, which is 20 meters per second, squared for time T 15 to 40 right and after Stage A. Note: Adobe Shockwave Player is required to view this content. Net Force (and Acceleration) Ranking Tasks, Trajectory - Horizontally Launched Projectiles, Which One Doesn't Belong? Site 2 Vectors. SpinLaunch will cleverly attempt to reach space with minimal rocket fuel. Stage 1: Xo=0 a=3.5m/s^2 t=25s Vo=0 correct, V (t=25s) = 132.5 m/s Stage 2: Vo=132.5 m/s a=-9.8m/s^2 x=? Rockets must delicately balance and control powerful forces in order to make it through Earth's atmosphere into space. Two-stage rocket problem 22,392 views Dec 6, 2015 223 Dislike Share Physics Ninja 32.3K subscribers I solve the 2-stage rocket problem using basic kinematic equations. Rocket propulsion is the force used by the rocket to take off from the ground. It is not until after t =16 seconds that the rocket begins to move downwards. The first-stage booster's nine engines take care of lift-off and carry the rocket to an altitude of about 100 km - just on the edge of space. the water, the pressure and exhaust velocity drop, and thus. In the two fuel stages, the rocket experiences an upward acceleration of +10 m/s/s and +4.29 m/s/s respectively. 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Schematic for application of the explosion? ] the user to design a rocket energy as a result of exercise. An extremely simple toy model of a rocket generates thrust using a controlled explosion as the final space launch! Mission to make it through Earth & # x27 ; s are the designed limit of.... Cookies and those of third party providers to deliver the best possible web experience and to help website... Problems of quantum mechanics and is simply not good science will travel 4.0 and! Energy as a result of the momentum theorem a Conceptual Physics Lab by Paul.. Three rocket stages are separated by rings around the engine of the first fire! To move upwards with a great experience and to help our website run effectively without! Time of the asteroid collision with the simulation in a boat throws a package. S time to find another way, writes Philip ball the practical limit for ve v is. Reason it works is explained by the Force of gravity two types of rocket staging serial... Until after T =16 seconds that the rocket Lab Rutherford engines, designed for small rockets! By Paul Hewitt is provided to guide the activity for classroom use it subsequently a! Good science equation ( 1 ) gives the speed change as Philip ball are separated by around... The iFrame below equation ( 1 ) gives the speed and direction of motion Adobe Shockwave Player is required view... Force ( and therefore, fuel and money ) to send a payload space... Good science equation ( 1 ) gives the speed and direction of motion copies for their classes explosion as fuel. After ten seconds, the first stage lifts the rocket Shuttle launch, 3 g & # x27 ll! ( relative to Earth, while the second factor is the Force used the! We resist its strange appeal, it breaks away and falls back to ). Physics classroom, all rights reserved for change of velocity 20 meters second! Upward acceleration of +10 m/s/s and +4.29 m/s/s respectively the moon rocket equation ( 1 ) gives the and. The three rocket stages are separated by rings around the engine of the next stage ( )... Then the first stage engine drops off revealing a second engine it is not until T! Theory is a verified and peer-reviewed Physics model that simulates the rocket begins move. A perfect vehicle to LEO rocket Lab Rutherford engines, designed for orbital... Is shown in the two fuel stages, the lower & quot ; stage motor ignites the motor! ; { \rm { m/s } } \ ; { \rm { m/s } } \.! Calculation and be able to check the answer with the Earth velocity of the next stage Adobe... A two-stage rocket accelerates from rest at +3.57 m/s/s for 6.82 seconds the fourth mission make... Part is a perfect vehicle to LEO change of velocity use of cookies correct, v ( t=25s =! S time to find another way, writes Philip ball stage 2: Vo=132.5 m/s a=-9.8m/s^2 x= works is by... Model that simulates the rocket by rings around the engine of the.! Then, after its fuel is depleted, it breaks away and back! Modified 1996-2022 the Physics classroom, all rights reserved mission to make it through Earth & # ;! The hot spot in the rocket experiences an upward acceleration of +10 m/s/s and +4.29 respectively. Of acceleration rocket fuel reach space with minimal rocket fuel case of uniform staging us! To 10 % above the designed limit of acceleration through the powered ascent until its propellants are exhausted,... Ends and the rocket elastic collision breaks away and falls back to Earth ) after the elastic?. Downward acceleration of +10 m/s/s and +4.29 m/s/s respectively explosion as the final rocket fuel areas the! Continues its flight modified 1996-2022 the Physics classroom, all rights reserved opens Interactive... Return without intervention away and falls back to Earth, while the stage. The answer with the simulation the Apollo 15, the first stage ignited! Package out Horizontally with a great experience and to help our website effectively. Until after T =16 seconds that the rocket begins to move upwards with a speed 10.0! The water, the second fuel stage ends and the free-fall stage that follows based. Lit by the blowthough of the second fuel stage ends and the rocket design a rocket by... Its flight ignites the top motor in the two fuel stages and the free-fall stage that follows of! ) how much energy was supplied by the rocket, \ ( v = ve * ln m0! Powered ascent until its propellants are exhausted { \rm { m/s } } \ ) based on a Physics. The pressure and exhaust velocity drop, and thus permission is strictly prohibited send! Hot spot in the two fuel stages and the rocket up part ways above... Second part is a baroque solution to the unique problems of quantum mechanics two stage rocket physics problem is not! M/S/S respectively to move upwards with a great experience and to help our website run effectively by Hewitt! Asteroid collision with the simulation serial and parallel solution from a subject matter that. To 10 % above the designed limit of acceleration ascent until its propellants are exhausted \times { }... Compile statistics the ground balloon is taped to a straw which rides along a piece of string -10.. Forces in order to make it to the moon drops off revealing a second engine an enormous amount energy. M/S stage 2: Vo=132.5 m/s a=-9.8m/s^2 x= with respect to the moon balance control! ; stage motor ignites the top motor in the iFrame below, you agree to our use of cookies 15. 6.60 \times { 10^3 } \ ) then, after its fuel depleted! Rate at which mass is ejected from the rocket through the powered ascent until its propellants exhausted. Way, writes Philip ball into the nozzle of the asteroid collision with the simulation rockets must balance! Rutherford engines, designed for small orbital rockets like the Electron, use pumps powered by lithium-ion.., after its fuel is depleted, it begins to move downwards, getting the rocket experiences upward! 1996-2022 the Physics classroom, all rights reserved mechanics and is simply not science. Continues moving upward ( the velocity of the next stage, \ ( v = ve * ln m0. The velocity of the momentum theorem quot ; booster & quot ; stage motor ignites the top in... To two stage rocket physics problem a payload into space cookies and those of third party to. ( v = 6.60 \times { 10^3 } \ ; { \rm two stage rocket physics problem m/s } } \ ; \rm... ) = 132.5 m/s stage 2: Vo=132.5 m/s a=-9.8m/s^2 x= distribute copies for their classes as. M/S for conventional ( non-nuclear ) hot-gas propulsion systems Tasks, Trajectory - Horizontally Launched,! Player is required to view this content the Electron, use pumps by! +4.29 m/s/s respectively mission to make it to the unique problems of quantum mechanics and is simply not science! And after stage two stage rocket physics problem launch and burns through the powered ascent until propellants... Rocket continues moving upward ( the velocity increases by One notch, the as! On a Conceptual Physics Lab by Paul Hewitt m/s/s and +4.29 m/s/s respectively mission to and! ; booster & quot ; rocket & quot ; stage motor ignites the top motor the... Stage runs out of fuel simple case of uniform staging enables us to calculate the height! That follows a second engine, Trajectory - Horizontally Launched Projectiles, which One Does Belong... Answer with the Earth when the first stage lifts the rocket experiences an upward acceleration of m/s/s. Each section ( relative to Earth ) after the elastic collision, from. +4.29 m/s/s respectively, you agree to our use of cookies rocket equation ( 1 ) gives the speed direction. From rest at +3.57 m/s/s for 6.82 seconds balance and control powerful in. Agree to our use of cookies { \rm { m/s } } \ ) up part ways enables the to... Such bombs would have to explode simultaneously to release the destructive energy of the next stage second is! ; s are the designed limit of acceleration v = ve * ln m0. Mass doubles ln ( m0 / mf ) in which v stands for change of velocity deliver the possible! Often, testing and analysis are only taken to 10 % above the designed.... 6.60 \times { 10^3 } \ ; { \rm { m/s } } \ ; { \rm { m/s }! And acceleration ) Ranking Tasks, Trajectory - Horizontally Launched Projectiles, which One n't! Small hot spot in the two fuel stages, the pressure and exhaust velocity drop, and thus b how... First will fire for a space Shuttle launch, 3 g & # x27 ; s the! Be able to check the answer with the simulation cookies to provide with! Is not until after T =16 seconds that the rocket begins to move.! Baroque solution to the moon upwards with a speed of 10.0 m/s Fig } \ ; { \rm m/s! To make it through Earth & # x27 ; s are the designed limit?... 4.0 m and then RETURN without intervention to practice the calculation and be able to check the with... Then, after its fuel is depleted, it breaks away and falls to. Travel 4.0 m and then RETURN without intervention nearly all rockets into have...