An aeroplane flies horizontally at a constant height of 1000 √3 m above the ground. From a fixed point on the ground its angle of elevation is 60°, and 10 seconds later, from the same point, its angle of elevation is 30°. Find the speed of the aeroplane in metres per second.

Question

Accepted Answer

200. First instant: tan 60 = 1000 √3d1 => d1 = 1000 m. Second instant: tan 30 = 1000 √3d2 => d2 = 1000 √3 x √3 = 3000 m. Distance flown = 3000 - 1000 = 2000 m in 10 s, so speed = 2000/10 = 200 m per second.

An aeroplane flies horizontally at a constant height of 1000 $3$ m above the ground.
From a fixed point on the ground its angle of elevation is 60°, and 10 seconds later, from the same point, its angle of elevation is 30°.
Find the speed of the aeroplane in metres per second.

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Heights and Distances practice

An aeroplane flies horizontally at a constant height of 1000 3​ m above the ground.From a fixed point on the ground its angle of elevation is 60°, and 10 seconds later, from the same point, its angle of elevation is 30°.Find the speed of the aeroplane in metres per second.

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Heights and Distances practice

An aeroplane flies horizontally at a constant height of 1000 $3$ m above the ground.
From a fixed point on the ground its angle of elevation is 60°, and 10 seconds later, from the same point, its angle of elevation is 30°.
Find the speed of the aeroplane in metres per second.