Two trains, 200 m and 140 m long, are running on parallel tracks in the opposite directions at a speed of 60 km/h and 30 km/h, respectively. What will be the time taken by the trains to cross each other completely?
The correct answer is 13\frac{15}{25} s.
This comes from 1 \text{ km} = 1000 \text{ m} and 1 \text{ hour} = 3600 \text{ seconds}, so 1 \text{ km/h} = \frac{1000 \text{ m}}{3600 \text{ s}} = \frac{10}{36} \text{ m/s} = \frac{5}{18} \text{ m/s}. To convert from \text{m/s} to \text{km/h}, multiply by \frac{18}{5}. Always check if all quantities are in compatible units (e.g., all in meters and seconds, or all in kilometers and hours) before performing calculations.
Similar Questions
A 315 - m - long train is moving at a speed of 24 km/h. It will cross a man coming from the opposite direction at a speed of 3 km/h in __________.
A thief seeing a policeman from a distance of 550 metres started running at a speed of 9 km/h. The policeman began to chase him immediately, at a speed of 11 km/h and the thief was caught. What is the distance run by the thief before he was caught by the policeman?
A person travels equal distances at speeds of 3 km/h, 4 km/h, 7 km/h and 12km/h, and takes a total of 680 minutes. What is the total distance (in km) travelled?
A person travels equal distances at speeds of 2 km/h, 4 km/h, 5 km/h, 7 km/h and 12 km/h, and takes a total of 1485 minutes. What is the total distance (in km) travelled (to the nearest integer)?
Two trains of length 150 m and 300 m long are going parallel in opposite direction at a speed of 90 m/min and 60 m/min respectively. What is the time taken for the trains to cross each other completely?
A policeman follows a thief, who is 840 meters ahead of him. The thief and the policeman run at a speed of 7.5 km/h and 9 km/h, respectively. What distance (in km) is run by the thief before he is nabbed by the policeman?
How long (in seconds) will a train of a length 320 m, running at a speed of 67 km/h, take to cross a man moving in the opposite direction at a speed of 5 km/hr?
A 2-m-long scooter moves past a plank completely in 5 s. The length of the plank is 3 m. What is the speed of the scooter?
A man travels a distance of 4 km every day. One day he increases his speed by 0.8 km/h than usual speed and reaches his destination 15 minutes earlier. What is the normal speed of the man?
Two trains 230 m and 270 m long, are running on parallel tracks in the opposite directions at a speed of 40 km/h and 50 km/h, respectively. What is the time taken by the trains to cross each other completely?
Important Questions from Relative Speed
In a circular race of 2500 m, a man and a woman start from a point towards opposite directions with speeds of 37 km/h and 35 km/h, respectively. After how much time from the start of the race will they meet for the first time?
- X and Yrun a 3 km race along a circular course of length 300 m. Their speeds are in the ratio 3 : 2. If they start together in the same direction, how many times would the first one pass the other (the start-off is not counted as passing)?
A train of length 600 meters passes another train of length 1000 meters moving in the opposite direction in 96 seconds. If the speed of both the trains is the same, then what is the speed of each train?
A train, running at a speed of 36 kmph, takes 60 seconds to cross an electric pole. How much time it will take to cross a platform of length 250 meter?
A truck covered a distance of 780 km in 12 hours. What distance would a car cover in 11 hours travelling at a speed which is seven kmph more than that of the truck?
