Peace to all. Studying and trying to get a handle on how to calculate like-minded questions, I came across this question from the web. I don't understand how exactly it was solved. How were the units canceled out and with what exactly?
To convert this measurement, we need to convert meters to miles and seconds to hours. To do this, we need the following relationships: 1000 meter = 1 kilometer; 1 kilometers = 0.621 mile; 60 seconds = 1 minute; 60 minutes = 1 hour; We can now set up the equation using these relationships so the units cancel out leaving only the desired miles/hour.
speedMPH = 2.998 x 10^8 m/sec x (1 km/1000 m) x (0.621 mi/1 km) x (60 sec/1 min) x (60 min/1 hr)
Note all the units canceled out, leaving only miles/hr: > > speedMPH = (2.998 x 10^8 x 1/1000 x 0.621 x 60 x 60) miles/hr > > speedMPH = 6.702 x 10^8 miles/hr
The speed of light in miles per hour is 6.702 x 10^8 miles/hr.