A sprinter set a high school record in track and field, running 200.0 m in 20.9 s . What is the average speed of the sprinter in kilometers per hour?

Answer 1

We will use dimensional analysis to convert from meters and second to kilometers and hours:

200.0 meters/ 20.9 seconds ( 1 kilometer/ 1000 meters) (60 seconds/ 1 minute )(60 minutes/1 hours) = 34.4 km/hour