Question
A boat is being rowed away from a cliff 270 m high. From
the top of the cliff, the angle of depression of the boat changes from 60° to 45° in 2 minutes. What is the speed of the boat?Solution
According to the figure above: tan 45° = 270/(a + b) ⇒ 1 = 270/(a + b) ⇒ a + b = 270 Also, tan 60° = 270/a ⇒ √ 3 = 270/a ⇒ a = 270/ √ 3 ⇒ a = 90√ 3 = 155.8 ∴ b = 270 - 155.8 = 114.2 ⇒ The boat covers a distance of 114.2 m in 2 minutes. ∴ Speed of the boat = (114.2 x 60)/(2 x 1000) km/h = 3.4 km/h
Baghmara Pitcher Plant Sanctuary is located in which of the following states?
Identify the financial Institution that has launched Care for Hockey campaign?
Who has been appointed as the next Ambassador of India to the Kingdom of Sweden?
NPCI sets_____ as a deadline to activate offline payments on RuPay cards.
As per World Gold Council data, which country’s central bank is the largest buyer of gold?
Who has been elected president for a third term in Egypt?
Where is the headquarters of FIFA (Fédération Internationale de Football Association) located?
Which university has built the first-ever subsea research lab in Asia for fostering multi-disciplinary talent for the global oil and gas industry?
In which year did Raja Rammohun Roy establish the Brahmo Samaj?
India has signed MoU with which country for Electoral Corporation?
