Question

A train travels a distance with a speed of 30 km h–1 and return with a speed of 50 km h–1. Calculate the average speed of the train.
(A) 40 kmh–1 (B) 37.5 kmh–1 (C) 10 15 kmh–1 (D) 45 kmh–1

Answer 1

Mark me as braimliest. FOLLOW METhe answer is option (b) 37.5km/h

because,

S/T = Speed, which can be written as T = S/Speed

Let, D be the distance traveled from initial position to the point till where the speed is 30km/h. Therefore total distance is S = 2D since it returns to its initial position. Also, let T1 be the time taken to travel D distance at a speed of 30km/h and T2 for 50km/h and the same distance.

Therefore, T1 = D/30 and T2 = D/50

Now, T1 + T2 = T which is D/30 + D/50 = 80D/1500

Therefore, Avg. Speed = Total distance covered/total time taken

Which is, = (D + D)/(80D/1500)

And there’s the answer.

Hope it helped :)

Answer 2

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⟼ QUESTION:-

⟼ A train travels a distance with a speed of 30 km h–1 and return with a speed of 50 km h–1. Calculate the average speed of the train.

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Illustration:-

1: A car travels a distance of 500 km in 10 hours. What is its speed in km/hr?

1: A car travels a distance of 500 km in 10 hours. What is its speed in km/hr?Sol: Speed = Distance/Time → 500/10 = 50 km/hr.

Sol: Speed = Distance/Time = 540/3x180 km/hr. To convert speed into m/s we need to multiply 180 by 5/18. So required speed = 180 × 5/18 =

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Let the two speeds be a kmph and b kmph. Let the distance traveled in each of the speeds be x km.

✒$Let the two speeds be a kmph and b kmph. Let the distance traveled in each of the speeds be x km.</em></p><p></p><p></p><p></p><p></p><p><em>✒</em><em>Time taken to cover x km at ‘a’ kmph = x/a & at ‘b’ kmph = x/b.Total time taken = and the total distance covered = 2x.</em><em>Therefore, average speed = $

SO, ANSWER IS OPPOSITION..

B.)37.5KMH-1.

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