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    Need some help with 5i.

    Not entirely sure. I tried first saying the speed it hits the ground is v^2=u^2+2as.
    U=5 so v^2=2as v^2=5^2+2×9.8×1.4. Which gave me v= 7.507
    Im not sure on the coefficent of resitution bit.
    Is it 0.7= 7.507/ speed the ball comes back or the other way round?

    Also what is the com of a semi circle?
    http://m.imgur.com/A11mEmK
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    (Original post by Super199)
    Need some help with 5i.

    Not entirely sure. I tried first saying the speed it hits the ground is v^2=u^2+2as.
    U=5 so v^2=2as v^2=5^2+2×9.8×1.4. Which gave me v= 7.507
    Im not sure on the coefficent of resitution bit.
    Is it 0.7= 7.507/ speed the ball comes back or the other way round?

    Also what is the com of a semi circle?
    http://m.imgur.com/A11mEmK

    Otherway around it should be speed the ball comes back up = 0.7 * 7.507.

    COM of a semi circle is \frac{4r}{3\pi} along its radius from the diameter.
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    (Original post by Zacken)
    Otherway around it should be speed the ball comes back up = 0.7 * 7.507.

    COM of a semi circle is \frac{4r}{3\pi} along its radius from the diameter.
    Sound. How did you get the com of a semi circle that?
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    (Original post by Super199)
    Sound. How did you get the com of a semi circle that?
    Should be in your formula booklet for "sector of circle" with the angle as 2\alpha, just set \alpha = \frac{\pi}{2} and you're good to go.
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    (Original post by Super199)
    Sound. How did you get the com of a semi circle that?
    Formula book for m2, it is proved in m3 i believe and involves some integration but you can almost certainly quote it as a standard result for your purposes
 
 
 
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