Question

an aeroplane is flyig at a height 3000m . an observer find his angle of election to b 60° and after 6src it changed to 45° what is spEed of aeroplae​

Answer 1

Answer:

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Step-by-step explanation:

Answer 2

Answer:

Step-by-step explanation:

Question :

An Aeroplane is flying at a height 3000m. An observer finds the angle of elevation to be 60° and after 6 seconds, it changed to 45°. What is the speed of aeroplane ?

Answer :

For speed, first we have to find distance

since, speed = distance/time

Distance = AB = EC = CD - ED

In ΔBDC,

tan 45° = BC/CD

1 = 3000/CD

∴ CD = 3000 m

In ΔADE,

tan 60° = AE/ED

√3 = 3000/ED [AE=BC]

ED = 3000/√3

ED = 3000 x √3/√3 x √3   [rationalising]

ED = 3000 x  √3/ 3

∴ ED = 1000√3 = 1000 X 1.7 = 1700m

AB = EC = CD-ED= 3000 - 1700 = 1300 m

speed = distance/time

= 1300/6

= 216.6 m/s