Question
Two guns were fired from the same place at an interval
of 20 minutes but a person in a train approaching the place hears the sound 16 minutes 30 seconds after the first. Find the speed of the train (in kmph) supposing that the sound travels 330 meters per second.Solution
The distance travelled by the train in 16min 30 seconds will be equal to that travelled by sound (20 min – 16 min 30 sec) = 3 min 30 seconds The train travelled 330 × 210 meters in 16 1/2 minutes. ∴ Speed of the train per hour = (330 × 210 × 2 × 60)/(33 ×1000) = 252 km/hr ALTERNATE METHOD: Let speed of train = x m/s The distance covered by bullet with a speed of sound 330m/s in 20 minutes is equal to distance covered by train & bullet together in 16 min 30 sec So let speed of train = x m/s So 330 × 20 = (x+330) × 16 × 1/2 6600 × 2/33 = x + 330 So x + 330 = 400 Or x = 70 m/s = 70 × 18/5 kmph = 252kmph
Which of the following is/are NOT a non-justifiable right?
1. Right to work
2. Equal pay for equal work (for men and women)
3. ...
Bharatiya Nyaya Sanhita was introduced in Lok Sabha to replace_______.
Who founded "Ramakrishna Mission" in 1897?
Infrastructure Investment Trusts, 2014 are regulated in the country by?
...The European Space Agency (ESA) is launching the JUICE mission, which aims to explore Jupiter's moons. What is the primary objective of the JUICE mission?
In the worst industrial accident in history, more than 40 tons of which of the following gas leaked from a pesticide plant in Bhopal?
Which of the follwoing statement is correct?Â
(i) Ahmad Shah Abdali fought the third battle of Panipat.
(ii) Babur established the Delh...
Who among the following represents the full authority of the Lok Sabha?
Which is the National Animal of India?
The bare ground between plants is covered with a layer of organic matter in order to retain soil moisture. This method is called ______.
Relevant for Exams:
