Calculate the Average Speed of an Airplane

What are the speeds and distances traveled by the airplane?

1. The airplane travels 2800 km at a speed of 700 km/h.

2. It decreases its speed to 500 km/h for the next 1500 km.

3. The airplane travels the last 1000 km at a speed of 400 km/h.

Answer:

The average speed for the airplane is 558 km/hr.

Calculating the Average Speed of the Airplane

To find the average speed of the airplane for the entire trip, we need to calculate the total distance traveled and total time taken. Let's break it down step by step:

Step 1: Calculate the time taken for the first part of the trip (at 700 km/h).

- Distance for the first part = 2800 km

- Speed for the first part = 700 km/h

- Time taken for the first part = 2800 km / 700 km/h = 4 hours

Step 2: Calculate the time taken for the second part of the trip (at 500 km/h).

- Distance for the second part = 1500 km

- Speed for the second part = 500 km/h

- Time taken for the second part = 1500 km / 500 km/h = 3 hours

Step 3: Calculate the time taken for the third part of the trip (at 400 km/h).

- Distance for the third part = 1000 km

- Speed for the third part = 400 km/h

- Time taken for the third part = 1000 km / 400 km/h = 2.5 hours

Now, let's calculate the total distance and total time for the entire trip:

- Total distance = 2800 km + 1500 km + 1000 km = 5300 km

- Total time = 4 hours + 3 hours + 2.5 hours = 9.5 hours

Finally, we can find the average speed of the plane for the entire trip:

- Average speed = Total distance / Total time = 5300 km / 9.5 hours ≈ 557.89 km/h