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5) On a 60 km track, a train travels the first 30 km with a uniform speed of 30 kmh ¹. How fast must the train travel the next 30 km so as its average speed will be 40 kmh ¹ for the entire trip?​

User Pagliuca
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1 Answer

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To find the required speed for the next 30 km, let's first determine the time it takes for the train to travel the first 30 km.

Time = Distance / Speed

Time = 30 km / 30 km/h

Time = 1 hour

Since the train needs to maintain an average speed of 40 km/h for the entire trip, and it has already spent 1 hour traveling the first 30 km, the remaining 30 km must be covered in the remaining time.

Remaining time = Total time - Time spent on the first 30 km

Remaining time = 60 km / 40 km/h - 1 hour

Remaining time = 1.5 hours - 1 hour

Remaining time = 0.5 hours

To find the speed required for the next 30 km, we'll use the formula:

Speed = Distance / Time

Speed = 30 km / 0.5 hours

Speed = 60 km/h

Therefore, the train must travel at a speed of 60 km/h for the next 30 km to maintain an average speed of 40 km/h for the entire trip.

User Dhawalk
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