Question

The angle of elevation of an aeroplane from a point on the ground is 60degree. after a flight of 15 seconds the angle of elevation changes to 30 degree. if the aeroplane is flying at a constant height of 1500 root 3 metre find the speed of the plant is this kilometre per hour​

Answer 1

Answer: Step-by-step explanation:

Answer 2

Step-by-step explanation:

Height of aeroplane =BD=CE=1500

3m and

∠BAE=60°

and CAE=30°

In triangle ADB

tan60° = AD

1500

3

⇒

3 = AD

1500

3

⇒AD=1500 m

In triangle CAE

tan30° = AE

1500

3

⇒

3

1 = AD

1500

3

⇒AE=1500×3=4500 m

Distance covered by plane in 15 seconds: BC=DE=AE−AD=4500−1500=3000 m

Speed of aeroplane = 15

3000

=200 m/s=720 km/hr