Average speed of a train
We will form a distance-speed-time table for every stage of the journey. If the distance from Goa to Delhi was 2000 km, how long will it take to get from Delhi to Bombay if the person maintains the speed equal to the average speed? The distance from Delhi to Bombay is 1400 km.Īnswer: This is a three-stage journey. From Goa, the person travels to Delhi in 34 hours. Practice Average Practice Questions here Three Stage JourneyĮxample 2: A person travels from Mumbai to Goa in exactly 8 hours with a speed of 120 km/hr. Let us see a few more examples where the journey is completed in three stages. So to find the average speed never use the formula of the averages but try to find the total distance covered and the total time taken. Hence the correct option here is C) 48 km/hr. Time = Distance / speed = 1800/40 = 45 hours. Now we have to find the time taken to travel from Bangalore to Haryana. This can be done as follows:ĭistance = (Speed)×(Time). Thus we can say that Distance = 60×30 = 1800 kilometers. Let us find the distance first from Haryana to Bangalore. That is wrong because the average speed is the total distance divided by the total time.
What was the average speed of the truck during the roundtrip?Ī) 50 km/hr B) 55 km/hr C) 48 km/hr D) 52 km/hrĪnswer: You may be tempted to find the average speed by summing up the speed and dividing by 2. It returns from Bangalore to Haryana on the same road with an average speed of 40 km/hr. Browse more Topics Under AveragesĮxample 1: A truck goes from Haryana to Bangalore with an average speed of 60 km/hr. Let the body cover a distance ‘a’ in time t 1, then a distance b in time t 2, c in time t 3 and so on, then the average speed of the body is found out by the following ratio:Īverage speed = (a + b + c + …)/ (t 1 + t 2 + t 3 + …). In this case when a body has different speed during different parts of the journey, we define the average speed as:Īverage Speed = (Total distance covered throughout the journey)/(Total time taken for the journey) If the distance between any two stations is 6km, what is the speed of the train?Īnswer: Here you can’t use the formula directly because as you may have observed the train has a different speed from A to B than from B to C. But what if there is an object that covers part of its journey with one speed and the other part with another speed? Let us say a train goes from station A to B in 2 minutes and from B to C in 3 minutes. If ‘D’ is the distance traveled in some time ‘T’ then the speed of the object for this journey or ‘s’ is equal to s = D/T. The speed of an object is found out by dividing the distance that the object covers by the time in which the object takes to cover this distance.