Name: ____________________________Date: ________________ Physics 20 Course Introduction Scientific Notation: Example: Convert 4638600000 into scientific notation 4.638600000 x 10 9 Example: Convert 0.00000475 into scientific notation 4.75 x 10 –6 Note: A positive exponent indicates a number greater than 1 and a negative exponent indicates a number smaller than 1. Example: Calculate the following. a) (4.50 x 103) (9.25 x 105) = b) (3.36 x 10–7) (5.50 x 104) = c) 7.73 x 10 4 8.24 x 10 5 Significant Digits The number 354 has 3 significant digits. The number 35.4 has 3 significant digits. The number 52 has ____ significant digits. The number 3.54 x 104 has ____ significant digits. The number 0.354 has ____ significant digits. The number 0.00354 has ____ significant digits. The number 35400 has ____ significant digits. The number 0.03540 has ____ significant digits. The number 0.00350040 has ____ significant digits. Rules For Multiplying and Dividing When multiplying or dividing, _________________________________________________ _____________________________________________. Physics 20 - Introduction 1 Name: ____________________________Date: ________________ Example: 3.3 x 0.134 = The answer is 0.4422 but since the least number of significant digits being used is “2”, the answer must be rounded off to “2” digits. Example: 3746 x 0.120 = The calculator answer is 449.52, but since the least number of significant digits is “3”, the answer is rounded off to 3 digits. Example: 3746 x 120 = The calculator answer is 449520, but since the least number of significant digits is “3”, the answer is rounded off to 3 digits. The answer must be about 450000, but that number has 6 digits. In this case, use scientific notation. Answer: a) (5.55 x 109 )(2.34 x 105 ) (2.58 x 104 )(7.27 x 105 ) b) (3.52 x 103 )(9.11 x 105 ) (1.48 x 104 )(2.33 x 105 ) x (7.12 x 106 )(2.34 x 105 ) (8.22 x 10 4 )(4.71 x 105 ) = = Rules for Adding and Subtracting Perform the calculation in your calculator. _________________________________________________________________________. _________________________________________________________________________. ____________________________________. Example: 34.65 + 4.235 = Calculator answer is 38.885. The least number of place holding after the decimal is “2”. Answer: 38.89 Example: 1356.245 + 245.33 – 0.0001 = Note: When adding mixtures of units, _________________________________. When calculating long series of numbers,_________________________________. Physics 20 - Introduction 2 Name: ____________________________Date: ________________ Order of Operations: 1. Algebra [ ans: a) -76 b) 18 c)-13 d) -36 e) 74 f) 4 ] b) 6 + 4[12 2 - (-3)(-1)] a)-27 + 6(-9) +5 c) (-6)2 – (-7)2 where x = -2, y = 3 and z = -1 d) 3 x 2 yz e) 7 xyz 4 y 2 x 2 f) 5 x 2 y xy xz z 2. Solve the following using calculators, using correct number of significant digits and convert to scientific notation. a) 0.003 × 2157 = ___________________ =_____________________ b) 1.5 0.2 = ___________________ =___________________ c) 147.5× 2.9×0.3000 = ___________________ =_____________________ d) 3.56+8.3+5.0+0.300 = _______________= ______________ e) (3.75 105 )( 4.255 10 1 ) = _______________= ______________ (4.110 7 )(0.160000888) f) (4.13 105 6.14 105 )(8.13 10 11 ) = _______________= ______________ (7.14 10 4 )(6.3110 2 ) g) (1.83 106 ) 2 (8.13 10 4 6.14 10 4 ) = _______________= ______________ 1.31 103 3. Convert to scientific notation with correct significant digits. a) 401.000 = ______________ b)603.4 = ____________________ c) 4.1 cm + 5.2 mm +0.43 cm = ________________________ = ______________ d) 5.6 m + 3.8 cm + 5.72 cm = _________________________ = ______________ Physics 20 - Introduction 3 Name: ____________________________Date: ________________ e) 6.31 L + 3.4 L + 5.73 mL = __________________________ = ______________ f) 4.7 cm +5.3 mm + 2.1 m = __________________________ = ______________ g) 5.63×103 + 2.1×103 = _____________________ = _______________ 4. Unit Conversion: Some the more common conversions (refer to appendix SR 7) 1 mile = 1.6 km 1 m = 3.281 ft 1 m = 1.094 yd 1 m = 39.37 in 1 cm = 0.3937 in 1 ft = 0.333 yd 1 N = 0.2248 lb Complete the following conversions. Show your work. a) 225 cm = _______________________m b) 55.7 m = _______________________ cm c) 325 mm = _______________________ km d) 200 mm =_______________________ cm e) 20 s =_______________________ min f) 450 min = _______________________ h Physics 20 - Introduction 4 Name: ____________________________Date: ________________ g) 35 h = _______________________s l) 25 m/s = _______________________km/h n) 125 kg/m3 =_______________________ g/cm3 o) 225 cm =_______________________ m q) 325 mi =_______________________ km s) 20 a =_______________________s Compute, expressing your answer in scientific notation to the correct number of significant digits: a) 10.41 g + 12 g + 27.8 g + 253 g = ___________________ g b) (23.6 m/s) (26 s) = ______________________m c) 459 g – 0.24 kg = ____________________ kg d) 3.7456 N = _______________________N/m2 2.15 m2 Physics 20 - Introduction 5 Name: ____________________________Date: ________________ e) 3.51 x 104 m = ____________________ m/s2 (2.19 x 102 s)(5.62 x 104 s) f) (6.49 x 10-5 km/h) (2.48 x 10-4 h) = _____________________ km Using your calculator, solve for the following: a) 245 x 543 x 2435 = ______________________________ b) 0.345 x 0.003284 x 12.4 = ____________________________ Express the answer to each calculation in properly rounded form. 1. Find the area of a rectangular region 4.125 m long and 3.1 m wide. 2. What is the perimeter of a triangle with sides 2.1 cm, 3.04 cm, and 5 cm? 3. A piggy bank contains 31 quarters. What is the total value of the money in the bank? 4. A car travels 143.6 km in 1.05 hours. At this rate, how far will the car travel in 3 .4 hours? 5. An opened box of candy is marked “net weight 65 9.” The mass of candy in the box is measured as 57.265 g. How much candy has been eaten? Physics 20 - Introduction 6 Name: ____________________________Date: ________________ 6. Density is found from the formula, density mass . What is the density of a cube of volume platinum with mass 9.070 g, if it measures 0.75 cm on a side? 7. Perform the following mathematical operations, expressing the answers to the correct number of significant digits. (a) 463.66 + 29.2 + 0.17= ____________________ (b) 426.66 – 39.2 = ____________________ (c) (2.6)(42.2) = ____________________ (d) (65)(0.041)(325) = ____________________ (e) (0.0060)(26)(55.1) = ____________________ (f) 3.265/2.35 = ____________________ (g) = ____________________ (h) 5.6 + 2.34 + 5.698 – 8.23 = ____________________ 8. If a gold atom is considered to be a cube with sides 2.5 x 10-9 m, in how many gold atoms could stack on top of one another in gold foil with a thickness of 1.0 x 10-7 m? 9. On the average, 1.0 kg of aluminum consists of 2.2 x 102 atoms. How many atoms would there be in a block of aluminum 10 cm by 1.2 cm by 15.6 cm, if the density of aluminum is 2.7 g/cm3. Physics 20 - Introduction 7 Name: ____________________________Date: ________________ Transposition of Formulae: Rearrange each of the formulae given below so that the variable in parenthesis is the subject of the equation. e.g. F ma (m) answer m F a EA , (d) d 1. F ma , (a) 2. C 3. P1 P2 , (A2) A1 A2 4. P A hpg , (g) 5. V2 V1 at , (V1) 6. V2 V1 at , (a) 7. F 8. V r 2 , (ω) 9. T 2 10. V2 V1 2as , (V1) GmM , (r) r2 L , (L) g Physics 20 - Introduction 8 2 2