Frank started out in his car traveling 45 mph. When Frank was 1/3 miles away, Daniel started out from the same point at 50 mph to catch up with Frank. How long will it take Daniel to catch up with Frank?
+130037 Conversion factor from mph to ft - per - sec =
mph * 88 / 60
45 mph = 45 * 88 / 60 = 66ft/s
50 mph = 50 * 88 / 60 = 220/3 ft/ s
1/3 mile = 5280 ft / 3 = 1760 ft = the distance that Daniel must close to catch Frank
The difference in their rates = Daniel's effective closing rate = ( 220/3 - 66 ) ft/s
So....the time (in seconds) to catch Frank is
Distance to close / eff. closing rate
(1760) /( 220/3 - 66) = 240 sec = 4 min
+37157 Daniel has to cover 1/3 mile at the difference in speeds (5 m/hr) to catch up
1/3 m / 5 m/hr = 1/15 hr = 4 minutes
