1. Dimensional Analysis Contents: Handy things to know Ways to convert Whiteboard practice

3. Handy things to know: TOC 1 hr = 60 min = 3600 sec 1 km = 1000 m .6214 mile 1 mile = 5280 ft = 1760 yards  1610 m 1 m  3.281 ft 1 yard = 3 feet Shortcuts: 1 m/s = 3.6 km/hr  2.237 mph, 1 mph  1.47 f/s (1.46666666…) 1 f/s .682 mph (.6818181818…)

4. Ways to convert units: TOC 1.Unit cancellation 2.Calculator’s built in (TI 85/86) 3.Conversion factors 4.Google Unit cancellation: 30. mph to ft/s: 30. mi(5280 ft)( 1 hr ) hr ( 1 mi )(3600 s) = 44 f/s (note the units canceling) Conversion factor: 30. mph to ft/s: (1 mph = 1.47 f/s) 30. mph x (1.47) = 44.1 = 44 ft/s (slightly off - what’s the “real” conversion factor?) Google: Type 30. mph in ft/s into the search bar Calculator (TI 85/86) 2 nd CONV, MORE, MORE, SPEED, 30 mi/hr > ft/s

5. Whiteboards: Conversions 11 | 2 | 3 | 4 | 52345 TOC

6. Convert 32 mile/hour to feet/second 5280 ft = 1 mi 3600 s = 1 hr 32 mi(5280 ft)( 1 hr ) = 46.933333 hr ( 1 mi )(3600 s) 47 f/s (2 sig figs) 47 f/s W

7. Convert 88.0 feet/second to mph 5280 ft = 1 mi 3600 s = 1 hr 88 ft( 1 mi )(3600 s) = 60 mph s (5280 ft)( 1 hr ) 60.0 mph W

8. Convert 27.2 m/s to km/hr 1000 m = 1 km 3600 s = 1 hr 27.2 m ( 1 km )(3600 s) = 97.92 km/hr s (1000 m)( 1 hr ) 97.9 km/hr W

9. Convert 110. km/hr to m/s 1000 m = 1 km 3600 s = 1 hr 110 km (1000 m)( 1 hr ) = 30.55556 m/s hr ( 1 km )(3600 s) 30.6 m/s W

10. Convert 110. km/hr to mph 1 km .6214 mile 3600 s = 1 hr ?? 110 km (.6214 mi) = 68.354 mph hr ( 1 km ) 68.4 mph W