- #1

physicsneek

- 4

- 0

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