Advertisements
Advertisements
प्रश्न
Two men on either side of a temple 75 m high observed the angle of elevation of the top of the temple to be 30° and 60° respectively. Find the distance between the two men.
उत्तर
Given the height of the temple AB = 75 m.
Now in right-angled ΔABC,
⇒ `"BC"/"AB" = cot 30°`
⇒ `"BC"/"AB" = sqrt3`
⇒ `"BC"/75 = sqrt3`
⇒ BC = 75√3 ....(i)
Also in right angled ΔABD,
⇒ `"BD"/"AB" = cot 60°`
⇒ `"BD"/75 = 1/sqrt3`
⇒ BD = `75/sqrt3 xx sqrt3/sqrt3`
⇒ BD = 25√3 ....(ii)
Now the distance between the two men = CD
= BC + BD
= 75√3 + 25√3
= 100√3
Hence, the distance between two men = 100√3 m = 173.2 m
APPEARS IN
संबंधित प्रश्न
A bus covers a distance of 240 km at a uniform speed. Due to heavy rain, its speed gets reduced by 10 km/h and as such it takes two hrs longer to cover the total distance. Assuming the uniform speed to be ‘x’ km/h, form an equation and solve it to evaluate ‘x’.
The horizontal distance between two towers is 120 m. The angle of elevation of the top and angle of depression of the bottom of the first tower as observed from the second tower is 30° and 24° respectively.
Find the height of the two towers. Give your answer correct to 3 significant figures
The height of a tree is `sqrt(3)` times the length of its shadow. Find the angle of elevation of the sun.
From the top of a light house 100 m high, the angles of depression of two ships are observed as 48° and 36° respectively. Find the distance between the two ships (in the nearest metre) if:
- the ships are on the same side of the light house,
- the ships are on the opposite sides of the light house.
A man on a cliff observes a boat, at an angle of depression 30°, which is sailing towards the shore to the point immediately beneath him. Three minutes later, the angle of depression of the boat is found to be 60°. Assuming that the boat sails at a uniform speed, determine:
- how much more time it will take to reach the shore?
- the speed of the boat in metre per second, if the height of the cliff is 500 m.
The angle of elevation of the top of a vertical cliff from a point 30 m away from the foot of the cliff is 60°. Find the height of the cliff.
Find the length of the shadow cast by a tree 60 m high when the sun's altitude is `30^circ`.
The angle of elevation of a tower from a point 200 m from its base is θ, when `tan θ = 2/5`. The angle of elevation of this tower from a point 120m from its base is `Φ`. Calculate the height of tower and the value of `Φ`.
With reference to the given figure, a man stands on the ground at point A, which is on the same horizontal plane as B, the foot of the vertical pole BC. The height of the pole is 10 m. The man's eye is 2 m above the ground. He observes the angle of elevation of C, the top of the pole, as x°, where tan x° = `2/5`.
Calculate :
- the distance AB in metres;
- angle of elevation of the top of the pole when he is standing 15 metres from the pole. Give your answer to the nearest degree.
From the top of a lighthouse 100 m high the angles of depression of two ships on opposite sides of it are 48° and 36° respectively. Find the distance between the two ships to the nearest metre.