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Quick Applied Maths question!

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  • 18-06-2008 10:41pm
    #1
    Adventure
    Registered Users Posts: 81 ✭✭


    The displacement x of a particle from a fixed point o at a time t is given by

    x = 8cos 6t + 15sin 6t

    Find when x = 0 for the first time. ( amplitude = 7)


    Anyone have any ideas?:confused:


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    #2
    postalservice
    Registered Users Posts: 362 ✭✭postalservice


    What question is this, as in what topic?
    Its scares me!


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    #3
    ZorbaTehZ
    Registered Users Posts: 2,149 ✭✭✭ZorbaTehZ


    I'll give it a shot...
    8Cos 6t + 15Sin 6t = 0
    Sin 6t/Cos 6t = -8/15
    Tan 6t = -8/15
    t = -0.082
    So after pi/2, it'll be back at 0 displacement from o, ie t=1.489.

    Edit: Actully I think you should be adding pi to it so that would make it t=3.0599


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    #4
    tabouli
    Registered Users Posts: 163 ✭✭tabouli


    Simple harmonic motion, is it? :?


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