The angle of elevation of a jet plane from a point on the ground is. After a flight of at the speed of , the angle of elevation changes to . If the jet plane is flying at a constant height, then its height is:
Given
The initial angle of elevation
The changed angle of elevation
Step 1 - Distance traveled
Speed
we know that,
distance traveled speed time
Step 2- the jet plane is flying at a constant height
Now,
Therefore, the jet plane is flying at a constant height of
Hence, Option A is correct.