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    A firework rocket starts from rest at ground level and moves vertically. In the first 3s of its motion, the rocket rises 27m. The rocket is modelled as a particle moving with constant acceleration. Find
    A) the value of a
    B) the speed of the rocket 3s after it has left the ground

    After 3s the rocket burns out. The motion of the rocket is now modelled as that of a particle moving freely under gravity
    C) find the height of the rocket above the ground 5s after it has left the ground

    I have found a) as 6 and b) as 18 but i am struggling with part c
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    (Original post by Jamiemcq17)
    A firework rocket starts from rest at ground level and moves vertically. In the first 3s of its motion, the rocket rises 27m. The rocket is modelled as a particle moving with constant acceleration. Find
    A) the value of a
    B) the speed of the rocket 3s after it has left the ground

    After 3s the rocket burns out. The motion of the rocket is now modelled as that of a particle moving freely under gravity
    C) find the height of the rocket above the ground 5s after it has left the ground

    I have found a) as 6 and b) as 18 but i am struggling with part c
    So at the height of 27m the rocket burns out and the motion is that of a particle with initial velocity 18m/s and acceleration -g m/s2 and you're looking at the displacement after 2 seconds. Add this displacement onto the 27m.
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    (Original post by RDKGames)
    So at the height of 27m the rocket burns out and the motion is that of a particle with initial velocity 18m/s and acceleration -g m/s2 and you're looking at the displacement after 2 seconds. Add this displacement onto the 27m.
    Ohhhh right thank you i thought the rocket fell when it burned out😂
 
 
 
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