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
'I % J + K % M * O + N', what is the direction of J with respect to M?
Which of the following expression is correct where X is to the north east of T?
What is the code for ‘manage’ in the given coded language?
One day, Priya left home i.e. A and cycled 15 km southwards reached point B, turned right and cycled 8 km to point C and turned right and cycled 15 km t...
What is the code for ‘ right it plus ’?
What is the code for ‘harm’?
Dinesh walks 2 km towards South and turns to his right and walks 3 km. He then turns to his right and walks 4 km and turns again to his right and walks ...
In a row of girls Sangeeta is 8th from the right and Kamla is 20th from the left. When Sangeeta and Kamla Interchange position, Ka...
G % B * S + U % R, what is the direction of G with respect to U?
‘ha’ is the code for
