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  1. #1
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    journey

    a particle starts from rest from A and moves to B with uniform acceleration . in the last 2 seconds of its motion it describes seven sixteenths of the whole distance and in the first second is describes 3m.find the distance from A to B and how long it took to travel to A to B.
    for the first second 3=.5a so a =6 and i also formed the equation 12+2u=6/17 s where s stands for total distance . i formed this equation through the area of a trapezium . dont know where to go next
    Last edited by markosheehan; Jan 15th 2017 at 09:20 AM.
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    Re: journey

    Quote Originally Posted by markosheehan View Post
    a particle starts from rest from A and moves to B with uniform acceleration . in the last 2 seconds of its motion is describes seven sixteenths of the whole distance and in the first second is describes 3.find the distance from a to b and how long it took to travel to a to b.
    for the first second 3=.5a so a =6 and i also formed the equation 12+2u=6/17 s where s stands for total distance . i formed this equation through the area of a trapezium . dont know where to go next
    What does this clause mean?
    in the first second is describes 3
    Does the number 3 have units?

    I'm sure you know how to write legible, correctly formatted sentences ... like starting the first word with a capital letter and ending with a period, and inserting a space before the next sentence. Try doing that to effectively communicate what you're describing/asking.

    Also, if A & B are points of reference, continue to describe those points with capital letters ... do not change to lower case.
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    Re: journey

    sorry i have edited it to the exact question
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    Re: journey

    Quote Originally Posted by markosheehan View Post
    A particle starts from rest from A and moves to B with uniform acceleration . In the last 2 seconds of its motion it describes seven sixteenths of the whole distance and in the first second it travels 3m. Find the distance from A to B and how long it took to travel to A to B.
    Let $t$ be the time it takes to travel the entire distance $d$ ...

    in the first second it travels 3m
    $\dfrac{1}{2}a(1^2) = 3 \implies a = 6 \, m/s^2$

    Total distance traveled ...

    $d = \dfrac{1}{2}at^2 = 3t^2$

    If the particle moves 7/16 of the total distance in the last two seconds, then it travels 9/16 of the total distance in the first $(t-2)$ seconds ..

    $\dfrac{9}{16} \cdot d = 3(t-2)^2$


    You now have two equations with two unknowns ($t$ and $d$) ... solve the system algebraically.
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