PHYS 16 Lecture 2 Math Review Friday September

PHYS 16 – Lecture 2 Math Review Friday, September 10, 2010

Agenda � Register clickers � Online homework and exam � Science math review � Before next time

Register clickers � Can A) B) Yes No you correctly answer A to this question? http: //kookaburra. com. au

Online homework & exam � Online Math Exam – Due Sunday at 11: 59 pm � Online Homework for next week – Due Tuesday at 11: 59 pm � Practice problems…

Science Math Review � Read Ch. 1 in your text � Significant Digits � Scientific Notation � Unit Analysis � Vectors

Math Review – Significant Digits � Digits that actually have meaning! ◦ All digits in a number except for trailing or leading zeros ◦ All digits that relate to the precision of the number � Examples ◦ ◦ ◦ ◦ 1. 001 234 900 0. 005 3. 4 45. 6 10 To write (4 sig figs) (3 sig figs) (1 sig fig) (2 sig figs) (3 sig figs) (1 sig fig) 900 and 10 with more sig figs need Sci. Not.

Math Review – Scientific Notation �A way of representing a number so that you can clearly see the significant digits and the order of magnitude ◦ 110 would be 1. 1 E 2 or 1. 1 x 102 � Examples ◦ ◦ ◦ ◦ 1. 001 234 900 0. 005 3. 4 45. 6 10 (1. 001 E 0) (2. 34 E 2) (9. 00 E 2 or 9 E 2) (5 E-3) (3. 4 E 0) (4. 56 E 1) (1. 0 E 1 or 1 E 1)

Accuracy vs. Precison � Accuracy = How close measurements are to the target � Precision = Spread in measurements Accurate, not precise Precise, not accurate

Math Review – Unit Analysis � Prefixes � Conversion ◦ ◦ 1 mm = ___? ___ m 0. 001 m 1 inch = ___? ___ cm 2. 54 cm � Solving Problems ◦ Make sure answer has the correct units

Math Review – Vectors � Ways to write Vectors ◦ 3 mph to the right or 3 mph to the east ◦ 5 mph at 45 degrees from x axis ◦ (3, 2) or � Magnitude, Direction, Components

Math Review – Vectors � Adding Vectors ◦ Break into components and add the components � Subtracting Vectors – Add the negative vector

For next time… � Do the Online Math Exam ◦ Get the Connect Access card ◦ Enter the course ID – in syllabus materials � Read Ch. 1 and Ch. 2 ◦ Ch. 1 won’t have any additional homework… ◦ Ch. 2 online homework will be due Tuesday at 11: 59 pm � Get course materials and make sure to register!