Advertisements
Advertisements
Question
Find the angle of elevation of the sun when the shadow of a pole h metres high is `sqrt(3)` h metres long.
Solution
Let the angle of elevation of the sun is θ.
Given, height of pole = h m
Now, In ∆ABC,
tan θ = `"AC"/"BC" = "h"/(sqrt(3)"h")`
⇒ tan θ = `1/sqrt(3)`
⇒ tan 30°
⇒ θ = 30°
Hence, the angle of elevation of the sun is 30°.
APPEARS IN
RELATED QUESTIONS
A person standing on the bank of river observes that the angle of elevation of the top of a tree standing on the opposite bank is 60°. When he moves 40 m away from the bank, he finds the angle of elevation to be 30°. Find the height of the tree and width of the river. `(sqrt 3=1.73)`
Two stations due south of a leaning tower which leans towards the north are at distance a and b from its foot. If α, β be the elevations of the top of the tower from these stations, prove that its inclination θ to the horizontal is given by `\text{cot }\theta =\frac{bcot alpha -a\cot \beta }{b-a}`
The angle of elevation of the top of a tower from a point A due south of the tower is α and from B due east of the tower is β. If AB = d, show that the height of the tower is
`\frac{d}{\sqrt{\cot ^{2}\alpha +\cot^{2}\beta `
The angle of elevation of the top of a building from the foot of the tower is 30° and the angle of elevation of the top of the tower from the foot of the building is 60°. If the tower is 50 m high, find the height of the building.
A person observed the angle of elevation of the top of a tower as 30°. He walked 50 m towards the foot of the tower along level ground and found the angle of elevation of the top of the tower as 60°. Find the height of the tower.
The angle of elevation of the top of a tower at a distance of 120 m from a point A on the ground is 45 . If the angle of elevation of the top of a flagstaff fixed at the top of the tower, at A is 60 , then find the height of the flagstaff [Use `sqrt(3)` 1.732]
As observed form the top of a lighthouse, 100m above sea level, the angle of depression of a ship, sailing directly towards it, changes from 30° and 60° . Determine the distance travelled by the ship during the period of observation.
A tree is broken by the wind. The top struck the ground at an angle of 30° and at a distance 30 m from the root. Find the whole height of the tree. (`sqrt(3)`=1.73)
A plane is observed to be approaching the airport. It is at a distance of 12 km from the point of observation and makes an angle of elevation of 60°. The height above the ground of the plane is ____________.
The angles of elevation of the top of the rock from the top and foot of 100 m high tower are respectively 30° and 45°. The height of the rock is ____________.