Two ships P and Q are travelling at night with constant velocities. At midnight, P is at the point with position vector(adsbygoogle = window.adsbygoogle || []).push({}); (20i + 10j)km relative to a fixed origin O. At the same time, Q is at the point with position vector (14i – 6j)km. Three hours later, P is at the point with position vector(29i + 34j)km. The ship Q travels with velocity12j km h–1. At time t hours after midnight, the position vectors of P and Q are p km and q km respectively. Find

(a) the velocity of P, in terms of i and j,

(b) expressions for p and q, in terms of t, i and j.

At time t hours after midnight, the distance between P and Q is d km.

(c) By finding an expression for PQ, show that

d^2 = 25t^2 – 92t + 29^2.

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Hi... another vectors question....

i get the answers to part a and and b... however, for C i dont really know how to do this one.... maybe im lacking the principles to this question. ... If anyone could walk me through part C.. it would really help...

Thanks :)

PS. Do you know of any good internet source that has extensive tutorials on vectors?

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# Homework Help: Another Vectors Question.

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