Question

explain how to find the speed of an aeroplane in km/hr in the following situation:

The angle of elevation of an aeroplane from a point A on the ground is 60°. After a flight of 30 seconds the angle of elevation changes to 30°. If a plane is flying at a constant height of 2700√3 metres, find the speed of the aeroplane .

Answer 1

Step-by-step explanation:

Height of aeroplane =BD=CE=1500

3

m and

∠BAE=60

0

and CAE=30

0

In triangle ADB

tan60

0

=

AD

1500

3

⇒

3

=

AD

1500

3

⇒AD=1500 m

In triangle CAE

tan30

0

=

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

Answer 2

Answer:

Here you go.Hope you can understand