Physics

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A rock (m = 1.5 kg) moving at 4.2 m/s north collides with a ball (m = 0.061 kg) that is initially at rest. What is the velocity of the rock after the collision if the velocity of the ball after the collision was 8.4 m/s north?

  • Physics -

    Initial north momentum = 1.5*4.2 = 6.3
    which is also the final momentum

    6.3 = .061 * 8.4 + 1.5 * v

    v = 3.86 m/s

  • Physics -

    All motion remains in the north direction. Apply conservation of linear momentum in that direction.
    Mrock*Vrock,initial = Mball*Vball + Mrock*Vrock,final

    1.5*4.2 = 0.061*8.4 + 1.5*Vrock,final
    Vrock,final = 3.86 m/s
    The rock's direction remains north (positive)

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