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    erin_mae13's Avatar
    erin_mae13 Posts: 1, Reputation: 1
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    #1

    Aug 28, 2011, 09:14 AM
    Vectors and 2D Kinematics
    Three ships V1

    A destroyer simultaneously fires two shells with the same initial speed at two different enemy ships. The shells follow the parabolic trajectories shown.
    1)Which ship gets hit first?
    Enemy 1
    Enemy 2
    Both ships are hit at about the same time.
    Unknown008's Avatar
    Unknown008 Posts: 8,076, Reputation: 723
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    #2

    Aug 28, 2011, 12:03 PM
    Is there supposed to be a picture? Because I can't find any... :(

    Anyway, see which shell covers the least distance. That gives you the ship being hit first. If the distance is the same, then they get hit simultaneously.
    jcaron2's Avatar
    jcaron2 Posts: 986, Reputation: 204
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    #3

    Aug 29, 2011, 01:03 PM
    Actually, you should determine which shell attains the lowest maximum altitude. THAT will be the one that hits first. The distance traveled cannot be used in this case because for any point less than the maximum distance, there are TWO possible trajectories that the shell could take to get there - a long one and a short one. For example, if the target was only a few meters away, the gunner could choose to aim almost directly at it and blast away. That would be the short way. On the other hand, the gunner could also aim almost straight up into the air, then fire a shell that traveled in a very high arc, eventually coming down on top of the target. That would be the long way.
    Unknown008's Avatar
    Unknown008 Posts: 8,076, Reputation: 723
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    #4

    Aug 30, 2011, 09:31 AM
    Lol, you know, every time I see the word shell, I think at one of the Mario minigames where you throw shells on ice to hit a target :p

    But on another note... let's take the distance I mentioned above as the total distance travelled and not the displacement :)
    jcaron2's Avatar
    jcaron2 Posts: 986, Reputation: 204
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    #5

    Aug 30, 2011, 10:11 AM
    LOL! Seems like it would be hard to sink a ship with one of those shells. ;)
    Unknown008's Avatar
    Unknown008 Posts: 8,076, Reputation: 723
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    #6

    Aug 30, 2011, 10:28 AM
    Hmm... nothing is impossible with Super Mario ;)

    EDIT: And I still somehow can't give you a rep :(
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