This is from the M1 review excercise Edexcel. I've managed to do a) b) and c) and but now I'm completely stuck. I'm no particular wizz at mechanics and getting stuck at d) means I'm suddenly uncertain about e) and f) :(.(adsbygoogle = window.adsbygoogle || []).push({});

Here is the question:

In this question i and j are horizontal unit vectors and at right angles to each other.

At 12:00 a helicopter A sets out from its base 0 and flies with speed 120 km h-1 in the direction of the vector 3i+4j.

a) Find the velocity vector of A

At 12:20 that day another helicopter B sets out from O and flies with speed 150 km h -1in the direction of the vector 24i + 7j.

b) Find the velocity vector of B

c) Find the position vectors of A and B at 13:00

d) Calculate the distance of A from B at 13:00

At 13:30 B makes an emergency landing. A immediately changes direction and flies at 120 km h-1 in a straight line to B.

e) Find the position vector of B from A at 13:30

f) Determine the time when A reaches B.

The answers I have so far are:

a) 72i +96j

b) 144i +42j

c) A = 72i +96j B = 96i +28j

The answers I'm supposed to get for the rest are:

d) 72.1km

e) 60i-95j

f) 14 26

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# Homework Help: Help me complete this question please!

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