Question

The distance from New York City, United States, to Lisbon, Portugal is 5420 km. A flight

takes 6 h and 40 min. What is the average speed of the plane in meters per second?

Answer 1

225 5/6 m/s ≈ 225.8 m/s ≈ 226 m/s

Explanation:

Speed is the ratio of distance to time. Here, we also need to do a units conversion.

Distance

There are 1000 m in 1 km, so the distance is ...

5420 km = 5420×(1000 m) = 5.42×10^6 m

Time

There are 60 seconds in a minute, and 3600 seconds in an hour, so the time is ...

(6 h)×(3600 s/h) +(40 min)(60 s/min) = 21600 +2400 s = 2.4×10^4 s

Speed

Then the speed in meters per second is found by dividing meters by seconds:

speed = (5.42×10^6 m)/(2.4×10^4 s) = 2.25833...×10^2 m/2

The average speed of the plane is 225 5/6 meters per second.