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Fri 8 May, 2009 07:11 am

1. A fire in a building B is reported on telephone to two fire stations P and Q , 20 km apart from each other on a straight road. P observes that the fire is at an angle of 60 degrees to the road and Q observes that it is at an angle of 45 degrees to the road. Which station should send its team and how much will its team have to travel?

2. An aeroplane flying horizontally 1 km above the ground is observed at an elevation of 60 degrees. After 10 seconds , its elevation is observed to be 30 degees. Find the speed of the aeroplane in km/hr

@aman,

On number 1, draw a triangle BPQ with PQ segment = 20, <PB (angle PB) = 60 degrees, and <QB = 45 degrees. You should have learned a formula which will give you the distance of the segments PB and QB based on the angle and the distance of the segment PQ.

Let me think on number 2 for a sec.

Draw two right triangles.

One with a vertical component of 1 KM, connected to a 60 degree angle.

The next with a vertical component of 1 km, connected to a 30 degree angle.

Find the change in the horizontal component, and convert to a speed by dividing by 10 seconds, 1/6 minute, or 1/360 hour.

@aman,

1. i don't care if anybody goes, i love to watch a good fire, however, if it's a big enough fire both houses will probably need to go

2. one thing for sure, it's flying fast enough to keep it airborne

@DrewDad,

DrewDad wrote:

Draw two right triangles.

One with a vertical component of 1 KM, connected to a 60 degree angle.

The next with a vertical component of 1 km, connected to a 30 degree angle.

Find the change in the horizontal component, and convert to a speed by dividing by 10 seconds, 1/6 minute, or 1/360 hour.

Ah you beat me. It took me a few minutes to figure out the speed conversion.