Kinematic Equations for a Rocket with Constant Acceleration: Homework Help

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Homework Help Overview

The discussion revolves around a kinematic problem involving a rocket that accelerates upward with constant acceleration until the fuel is exhausted. Participants are exploring the implications of this scenario on the rocket's final height after fuel depletion.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the application of kinematic equations to determine the rocket's height, questioning the initial conditions and subsequent motion after fuel exhaustion. There is a focus on understanding the role of initial velocity and acceleration during different phases of the rocket's flight.

Discussion Status

Some participants have identified the need to consider the rocket's continued ascent after fuel depletion, leading to further inquiries about the initial conditions and the effects of gravity. Guidance has been offered regarding the interpretation of the problem and the importance of distinguishing between different phases of motion.

Contextual Notes

There is a mention of potential confusion regarding the kinematic equations and the specific parameters involved, including the initial velocity and the effects of gravity after fuel is exhausted. Participants are navigating through these assumptions without reaching a definitive conclusion.

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Homework Statement



A Rocket initially at rest on the ground accelerates straight upward from rest with constant net acceleration a, until time t_1 where fuel is exhausted.

Homework Equations





The Attempt at a Solution



I thought that putting these values into the kinematic equation

y = Vi(t) + 1/2*a*t^2 would be good but the answer is not 1/2(a)t^2 it is

H = .5(a)t + (.5*a^2*t^2)/g
 
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What is the problem asking for? Final height of the rocket? If so, remember that the rocket will still go up for a while after the fuel is exhausted, adding another distance to the one you have found. What's the initial velocity and what's the acceleration for the second part of this problem?
 
yes

yes it is asking for final height thank you I did not think of it still going up after running out of fuel I was thinking of it falling back down immediatly
 
physstudent1 said:

Homework Statement



A Rocket initially at rest on the ground accelerates straight upward from rest with constant net acceleration a, until time t_1 where fuel is exhausted.

Homework Equations





The Attempt at a Solution



I thought that putting these values into the kinematic equation

y = Vi(t) + 1/2*a*t^2 would be good but the answer is not 1/2(a)t^2 it is

H = .5(a)t^2[/color] + (.5*a^2*t^2)/g
see typo in red, now continue per Chi Meson's hint above.
 

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