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Stuck on another vectors question about intercepting boats Watch

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    A small boat S, drifting in the sea, is modelled as a particle moving in a straight line at constant speed. When first sighted at 0900, S is at a point with position vector (-2i-4j)km relative to a fixed origin O, where i and j are unit vectors due east and due north respectively. At 0940, S is at the point with position vector (4i-6j)km. At time t hours after 0900, S is at the point with position vector skm.

    a) Calculate the bearing on which S is drifting. (108)
    b) Find an expression for s in terms of t. (-2+9t)i + (-4-3t)j
    at 1100 a motor boat M leaves O and travels with constant velocity (pi+qj)kmh-1
    c) Given that M intercepts S at 1130, calculate the value of p and the value of q

    I've done parts a and b but need some guidance on c, don't even know where to start.
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    Anyone?
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    (Original post by Nida123)
    Anyone?
    Perhaps so, but not in the time you want.

    Have you got any info written down where you have set the i and j components equal?
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    I don't get how you would set the I and I components equal because I haven't got a position vector for m :/ I know the position vector of m would equal the position vector is s at 1130 but I don't know how I would do that, does it involve using the equation from b. I'm really confused
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    (Original post by Nida123)
    I don't get how you would set the I and I components equal because I haven't got a position vector for m :/ I know the position vector of m would equal the position vector is s at 1130 but I don't know how I would do that, does it involve using the equation from b. I'm really confused
    Use part (b) to work out where S is at 11:30. This will be a vector like mi + nj where m and n are just numbers.

    Using the speed vector they've given you for M, work out where M will be at 11:30 (be careful, because M's "time" starts at 11:00, not 09:00)

    Set the 2 position vectors equal to each other, and equate the i and j components.
 
 
 
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