An aeroplane flying horizontally 1km above the ground is observed at an elevation of 60degree. After a flight of 10 seconds it's angle of elevation is observed to be 30 degree from the same point on he ground. Find the speed of the aeroplane in km/hour

1 answer

tan 60 = X1/1
tan 30 = X2/1

d = X2 - X1

v = d/t

t in hours = 10 s /(3600 s/hour)