자유아카데미 최신분석화학 4판 솔루션 해리스/

Circuit Variables

1

Assessment Problems
AP 1.1 Use a product of ratios to convert two-thirds the speed of light from meters per second to miles per second: 2 3 × 108 m 100 cm 1 in 1 ft 1 mile 124,274.24 miles · · · · = 3 1s 1m 2.54 cm 12 in 5280 feet 1s Now set up a proportion to determine how long it takes this signal to travel 1100 miles: 124,274.24 miles 1100 miles = 1s xs Therefore, x= 1100 = 0.00885 = 8.85 × 10?3 s = 8.85 ms 124,274.24

AP 1.2 To solve this problem we use a product of ratios to change units from dollars/year to dollars/millisecond. We begin by expressing $10 billion in scienti?c notation: $100 billion = $100 × 109 Now we determine the number of milliseconds in one year, again using a product of ratios: 1 year 1 day 1 hour 1 min 1 sec 1 year · · · · = 365.25 days 24 hours 60 mins 60 secs 1000 ms 31.5576 × 109 ms Now we can convert from dollars/year to dollars/millisecond, again with a product of ratios: $100 × 109 1 year 100 · = = $3.17/ms 9 …(생략)