Question
The angle of elevation of an aeroplane from a point on
the ground is 60°. After 12 seconds flight the elevation changes to 30°, if the aeroplane is flying at a height of 1440√3 m. find the speed of the aeroplane.Solution
Distance between two place in which angle change is D = n(cotθ₁ + cotθ₂) Distance = 1440√3 (cot30° + cot60°) = 1440√3 × √3 - 1/√3 = 1440√3 × 2/√3 = 2880 m So, distance covered by plane in 12 sec = 2880 m Speed of plane = 2880/12 = 240 m/sec.
The fall in (A)/the number of deaths from heart disease (B)/are generally attributed to (C)/improvements in diet (D).
If it will (A)/rains tomorrow, (B)/I will bring (C)/an umbrella to stay dry.(D)
Americans are accustomed to (a) / drinking coffee (b) / with their meals (c) / No error (d)
He denied to have (A)/any part in writing the information packs (B)/and advertisements and said they (C)/were largely available when he arrived (D).
During the summer vacation, we plan to visit several cities / to explore their rich history / and learning about / their cultural heritage.
...Mischief are sure to (1)/crop up, in one form (2)/or another, among (3)/the idle and ambitionless (4).
Parts of the following sentence are given as options. Identify the segment that contains a grammatical error.
She has been working with me on t...
In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option...
Newborns in India have a least chance of survival than babies born in Afghanistan and Somalia.
Parts of the following sentence are given as options. Identify the segment that contains a grammatical error.
I am indebted to my friends for t...