the angle of elevation of a jet plane from a point a on the ground is 60 degree after a flight of 15 seconds the angle of elevation changes to 30 degrees if the jet plane is flying at a constan height of of 14500 root 3 metre find the speed of the plane
Answers
Answered by
1
In triangle AEB,
tan 60 = EB/ AB
√3 = 14500√3/AB
AB = 14500√3/√3 = 14500m
Now,
In triangle ADC,
tan 30 = DC/AC ⇒ tan 30 = DC/ AB+BC
1/√3 = 14500√3/ 14500+BC
14500 + BC = 14500√3 × √3 = 14500 × 3 = 43500
∴ BC = 43500 - 14500
∴ BC = 29000m
Speed = Distance/ Time
= 29000/15
= 1933.33 m/s or 5800/3 m/s
Attachments:
Similar questions