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    hi stuck on this question
    Two spheres A and B of equal radii and masses mkg and 2mkg respectively are moving in the same direction along a straight line. A has speed kums-1 (k>1) and B has speed ums-1. After A hits B it is brought to rest. The coefficiet of restitution between A and B is e.
    a) show that e = k+2 / 2(k-1
    b) deduce that k >_ 4
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    (Original post by xosarcycowxo)
    hi stuck on this question
    Two spheres A and B of equal radii and masses mkg and 2mkg respectively are moving in the same direction along a straight line. A has speed kums-1 (k>1) and B has speed ums-1. After A hits B it is brought to rest. The coefficiet of restitution between A and B is e.
    a) show that e = k+2 / 2(k-1
    b) deduce that k >_ 4
    Have you done any working? Draw a diagram, and write out what e is in terms of the velocities before and after.
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    think i've done it but not sure =/ lol
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    (Original post by xosarcycowxo)
    think i've done it but not sure =/ lol
    It's two "show that"s - it should be fairly obvious if you've done it :P
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    i know that but I start making it fit whether it does or not lol just to try and get the right outcome
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    I'm also stuck on this, no idea where the 2's and brackets are coming from.
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    (Original post by xosarcycowxo)
    i know that but I start making it fit whether it does or not lol just to try and get the right outcome
    Post what you've done so far - help us to help you
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    (Original post by tommm)
    Post what you've done so far - help us to help you
    I did the following.

    m1u1+m2u2 = m1v1+m2v2

    (m * ku) + (2m * u) = (m * 0) + (2m * v2)

    m1v1 cancel out because of a multiple of 0 so then the equation becomes.

    (m * ku) + (2m * u) / 2m = v2

    I'm not sure where to go from here because of moving terms about.
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    (Original post by ThrashMetal)
    (m * ku) + (2m * u) / 2m = v2
    I'm not sure where to go from here because of moving terms about.
    Your bracket's a bit off - after dividing by 2m, you should get:
    \frac{(m * ku) + (2m * u)}{2m} = v_2.
    Now, what is e = \frac{v_2-v_1}{u_2-u_1}?
 
 
 
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