SCIENTIFIC NOTATION & DIMENSIONAL ANALYSIS I. SCIENTIFIC NOTATION A. Basics: Scientific notation is useful when numbers are very _________ or _________. The original number is converted into a more manageable expression. The first number in the expression must be at least____ but less than ________. If the original number is a _____________ then the exponent is negative. If the original number is _______ or greater then the exponent is positive. Examples: Change to scientific notation 1) 0.000 000 045 =_______________ 2) 323,300 = _______________ 3) 3400 = ____________________ 4) 0.000 99 = ______________ Change to ordinary notation: 1) 5.45 x 106 =________________ 2) 6.1114 x 10-4 = _______________ 3) 4.3 x 104 = ________________ 3) 8.9 x 10 II. -7 = ________________ DIMENSIONAL ANALYSIS (D.A.) D.A. is a _____________________ method often used in physics. Conversion Factor (CF): Relates 2 different units that are ________ to each other Examples of CFs:__________________________________________________ General Format for D.A.: New Value = (Given #) x (CF 1) x (CF 2) x (CF3) …. The KEY to using Dimensional Analysis is to _______________ out _________________ until you get the ______________ you want. Example 1: How many minutes are in 1 MHS school day? Given/Know: Plan: Solve: Example 2: If you can drive 12 hours in 1 day at an average speed of 45 miles per hour, how long will it take you to drive to New Mexico, which is 3450 miles away? Given/Know: Plan: Solve: Example 3: How many seconds have you been alive? Given/Know: Plan: Solve: Remember: 1) Write out all the steps before multiplying. 2) Check to make sure your answer makes sense! SCIENTIFIC NOTATION & DIMENSIONAL ANALYSIS III. SCIENTIFIC NOTATION A. Basics: Scientific notation is useful when numbers are very large_____ or small_____. The original number is converted into a more manageable expression. The first number in the expression must be at least_1_ but less than ____10____. If the original number is a _decimal_______ then the exponent is negative. If the original number is __one_____ or greater then the exponent is positive. Examples: Change to scientific notation 1) 0.000 000 045 =______4.5 x 10-8_ 2) 323,300 = ___3.233 x 105__ 3) 3400 = 3.4 x 103 4) 0.000 99 = 9.9 x 10-4 Change to ordinary notation: 1) 5.45 x 106 =____5,450,000___ 2) 6.1114 x 10-4 = ____0.00061114_ 3) 4.3 x 104 = 43000 4) 8.9 x 10 -7 = _0.000 000 89 IV. DIMENSIONAL ANALYSIS (D.A.) D.A. is a ____problem solving___________ method often used in physics. Conversion Factor (CF): Relates 2 different units that are _equal__ to each other Examples of CFs:_(1in = 2.54cm) (1mL = 0.034oz)_(1gal = 3.8L) (1mi = 1.6km) General Format for D.A.: New Value = (Given #) x (CF 1) x (CF 2) x (CF3) …. The KEY to using Dimensional Analysis is to _cancel________ out _units___________ until you get the ___units________ you want. Example 1: How many seconds are in 5 MHS school days? Given/Know: (1 MHSday = 6hr) (1 hr = 60 min) (1 min = 60 s) Plan: day hour min sec Solve: 5 day (6hr/day)(60 min/ 1hr) = 1800 min Example 2: If you can drive 12 hours a day at an average speed of 45 miles per hour, how long will it take you to drive to New Mexico, which is 3450 miles away? Given/Know: (12hr=1day) (1 hour = 45 miles) Plan: miles hours days Solve: 3450 mi (1 hr/ 45 mi) (1 day/ 12 hr) = 6.38888 = 6.39 days Example 3: How many seconds have you been alive? 17 yrs(365 days/1yr) (24hr/day) (60 min/hr) ( 60s / min) = 536,112,000 s