Question

A bird was flying in a line parallel to the ground from north to south at a height of 2000m . Tom , standing in the middle of the field , first observed the bird in the north at an angle of 30° . After 3 minutes , he again observed it in the south at an angle of 45° . Find the speed of the bird in kilometres per hour .
$\sqrt{3 } = 1.73$
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Answer 1

Answer:

Answer:109.20

Step-by-step explanation:a bird is flying to north at an angle of elevation of 30°.

Using tan 30°=opp/adj

=1/√3=2000/BC

BC=2000√3m-------------(1)

Now, the bird fly to south at an angle of elevation of 45°

= tan45°=opp/adj

=1=2000/CD

=CD=2000m----------------(2)

Therefore,distance=BC+CD

2000√3+2000 =2000(√3+1)m

But we want the answer in km

2000(√3+1)/1000 = 2(√3+1)km

Bird takes 3min=3/60hr

Therefore,speed=distance/time

=2(√3+1)/3/60

=2(√3+1)×60/3

=20(2√3+2)

=40√3+40. (√3=1.73)

=40×1.73+40

=69.20+40

=109.20km/hr

Answer 2

Answer:

Step-by-step explanation: