Relevance of Physics to Life

 Why you feel cold when you have fever.  Why you choose to reduce energy consumption at home.  What happens to your mental capacity when your body lacks sleep.  Why most computer parts and accessories are painted black.  Why girls mature first than boys, get pimples first than boys.  Why boys become aggressive when they reach puberty.

 How do you demonstrate understanding of the relevance of Science and technology to daily life?

SCIENCE LIFE Responsible living Productive living Progressive culture Improved quality of living Conservation Preservation Health and Fitness Green technology Conservation Preservation Health and Fitness Green technology Computers and gadgets Productivity tools Computers and gadgets Productivity tools Communicat ion Education Medicine Communicat ion Education Medicine Improved media More diversity in skills Improved media More diversity in skills

When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot measure it, when you cannot measure it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts advanced to that stage of a science. - Lord Kelvin

 Qualitative vs. Quantitative Data  Qualitative descriptions are sometimes subjective and difficult to replicate.  Quantitative descriptions are numeric and can be replicated with a degree of exactness.

 Compare the physical quantity to a standard.  Self study: The different standards; Table 1-1

 How do you “measure” the character of a person around you? What is your standard?

 Where does Science start and to where does it lead?

 Start of science – desire to find the truth and establish a fact (observation, measurement, experiment)  Quantitative – more accurate (than …), obtained through measurement  Measurement – compare with standard

 Determine the number of significant digits in the numbers below The rules of significant figures does not apply to the figures above. The rules apply only to measurements.

 Count the number of significant digits in the figures given cm km cc

m s kg L 5. 56,000 nm ml cm s 10. mi

REVIEW AND PREPARE Quiz yourself with the items on page 25, numbers Write your answer just below the exercise you shaded yellow. Prepare to volunteer to show your answers on the board. TELL ME WHAT YOU THINK Study page 20 of your book. Focus on rule # 2, sample 1.11 and prepare to share insights on this example. Write your insight just below your exercise result that is shaded green. Prepare to discuss it with a pair and with the group. TELL ME WHAT YOU THINK Study page 20 of your book. Focus on rule # 2, sample 1.11 and prepare to share insights on this example. Write your insight just below your exercise result that is shaded green. Prepare to discuss it with a pair and with the group. REMEDIAL

 Determine the number of significant digits in the following figures mm cm kg 5. 6,500 tons seconds watts

 What’s with all the counting?

 Accuracy describes how close the measurement is to correct value.  Precision describes how well a certain measurement is replicated.

 The measure of the thickness of wood and its width are given as follows: TRIAL #THICKNESSWIDTH mm3 cm mm3 cm mm3 cm mm3 cm Average2.165 mm3 cm

 Why do we count significant digits in measurement (only)?  Why are the rules like that?  In counting the significant digits  In addition (subtraction)  In multiplication (division)

 The number of significant digits describe the degree of accuracy of the measurement.  Between these measurements, which is obtained using a better tool?  3 cm  2.18 nm  3.00 cm

 Accuracy of measurement is quantified using significant figures.  (depending on the tool and the skill) greater SF – more accurate  A measurement is a comparison to a standard.  Like when you say 1.5 kg, you are actually saying “one and a half of the Le Grand K.”  So 1.5 itself is meaningless without that kg unit.

 When a measurement is converted, its level of accuracy must be preserved.  Examples:  3 cm 0.03 m3x10 7 nm km  12 in1.0 ft0.33 yd

 Convert the following measurements in the units indicated kl toml nmtocm 1.0x10 6 ml 1,ōoo,ooo ml 4x10 -6 cm cm Answers

Answer this exercise. ½ crosswise The human brain is a super computer. It can store 10ō trillion bits of information. Express this number using all the prefixes h, da, d, c, m, and a in table 1-2. ( Observe the correct scientific form) Answer this exercise. ½ crosswise The human brain is a super computer. It can store 10ō trillion bits of information. Express this number using all the prefixes h, da, d, c, m, and a in table 1-2. ( Observe the correct scientific form) REMEDIAL

 1.00x10 12 hb  1.00x10 13 dab  1.00x10 15 db  1.00x10 16 cb  1.00x10 17 mb  1.00x10 32 ab

 Convert the following measurements in the units indicated gtoμg kmto pm kBtoGB clto L nFto μ F

 Convert the following measurements in the units indicated cmto km Lto kl μgto ng 4. 75,000 mgtocg ,ō00 nmtokm

 Directions will be represented by the axes of a Cartesian plane.  North and East take the positive direction, South and West the negative direction. N E W S

 A = 10m Northeast  B = 5m East A B R

 O = 10m 30 O North of East  P = 5m East O P R

 M = 10m 30 O East of North  N = 5m East M N R

 A = 30m S30 o E  B = 15m W6o o N

 Simple Triangles (Right Triangles)  M = 10m North  N = 5m East  R 2 =M 2 +N 2 M N R

 M = 10m 30 O East of North  N = 5m East M N R θ

 Open your book on page 45.  Show your solution for #s 1, 2 and 4 of letter B.  Point distribution  #1 – 5pts. (5 minutes)  #2 – 10pts. (10 minutes)  #4 – 5 pts. (5 minutes)  Use your notebook  #1 will be checked first before you solve for #2.

 Express your final answers in 2 SF.  Always use figures using 2 digits after decimal point for computation of final answers.  No partial points for wrong answers.  Deductions for R and angle: ▪ -1 eachwrong/no unit ▪ -1 eachwrong SF ▪ -1 eachimproper placement of sign

24 m, 25 O 120 m, -84 O 1.6 m, -39 O

 The difference between each pair of the following terms must be in your notebook or in your head.  Scalar vs. vector quantity  Distance vs. displacement  Speed vs. velocity  Uniform motion vs. accelerated motion  Kinematics vs. Dynamics