Write these down while you wait 1 hr

Write these down while you wait: 1 hr = 60 min = 3600 sec 1 km = 1000 m . 6214 mile 1 mile = 5280 ft = 1760 yards 1609 m 1 m 3. 281 ft 1 yard = 3 feet Shortcuts: 1 m/s = 3. 6 km/hr 2. 237 mph, (mph = miles/hour) 1 mph 1. 47 f/s (1. 46666666…) 1 f/s . 682 mph (. 681818…) Answer This Question: How many feet per second is 30 mph? (use any method you want – including help from others – but have an answer)

Write these down while you wait: 1 hr = 60 min = 3600 sec 1 km = 1000 m . 6214 mile 1 mile = 5280 ft = 1760 yards 1609 m 1 m 3. 281 ft 1 yard = 3 feet Shortcuts: 1 m/s = 3. 6 km/hr 2. 237 mph, (mph = miles/hour) 1 mph 1. 47 f/s (1. 46666666…) 1 f/s . 682 mph (. 681818…) Answer This Question: How many feet per second is 30 mph? (use any method you want – including help from others – but have an answer) (30 mph)(1. 4666666) = 44 ft/s (30 mi)(5280 ft)(1 hr) ( hr )( 1 mi )(3600 s) = 44 ft/s

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

Ways to convert units: Unit cancellation: 30. mph to ft/s: 1. 2. 3. 4. Unit cancellation Calculator’s built in (TI 85/86) Conversion factors Google 30. mi(5280 ft)( 1 hr ) hr ( 1 mi )(3600 s) = 44 f/s (note the units canceling) Calculator (TI 85/86) 2 nd CONV, MORE, SPEED, 30 mi/hr > ft/s 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 (text it to 466453? )

Whiteboards: Conversions 1|2|3|4|5 TOC

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

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

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

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

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

A car traveling 80. km/hr will go how far (in meters) in 2. 7 seconds? 1000 m = 1 km 3600 s = 1 hour (60 x 60) (km/hr)/(3. 6) = m/s 80. km/hr(1000 m/km)(3600 s/h) = 22. 22 m/s v = x/t 22. 22 m/s = x/(2. 7 s) x = (22. 22 m/s)(2. 7 s) = 60 m= 60. m W

A car goes 132 feet in 3. 1 seconds. What is its speed in miles per hour? v = x/t v = (132 f)/(3. 1 s) = 42. 5806 f/s(3600 s/h)/(5280 f/mi) = 29 mph 170 f W

A Baseball going 75 mph takes how much time to go 90. feet? 1 mile = 5280 feet 3600 s = 1 hour (60 x 60) 1 mph = 1. 47 f/s (1. 466666. . . f/s) 75 mi/hr(5280 ft/1 mi)(1 hr/3600 s) = 110 f/s v = x/t 110 f/s = (90. f)/t t = (90. f)/(110 f/s) =. 81818 s =. 82 s W