Question

21. The angle of elevation of the top of a chimney from the foot of a tower is 60% and the angle of
depression of the foot of the
chimney from
the top of the tower is 30° I the height of towers
40m, find the height
of smoke emitting
chimney. According to pollution control norms, the
minimum height of a smoke emitting chimney should be 100 m
​

Answer 1

Given : the angle of elevation of the top of a chimney from the top of a tower is 60 degree and the angle of depression of the foot of the chimney from the top of the tower is 30 degree. if the height of the tower is 40m

To find : height of the chimney

Solution :

Tower height = 40 m

Let say chimney Height = H m

Chimney height above tower = H - 40 m

Horizontal Distance between tower & chimney = D m

angle of elevation of the top of a chimney from the top of a tower is 60°

=> Tan 60 = (H - 40)/ D

=> √3 = (H - 40)/ D

=> D√3 = H - 40

angle of depression of the foot of the chimney from the top of the tower is 30°

=> Tan 30 = 40/D

=> 1/√3 = 40/D

=> D = 40√3

=> D√3 = 120

H - 40 = 120

=> H = 160

Chimney height = 160 m

120 m above tower height

Meetings the pollution Norms

Meetings the pollution NormsHence obeying the law & environment friendly