Welcome to Physics 1050 Concepts of Physics
What’s the Point? • Physics is basic • Physics explains things • Physics is the secrets of the universe
First Last Your Name Who are You? • Please clearly write your first and last name on the tent card • Please bring your tent card to every class
Group Work Introduce yourself to your group. Identify something memorable about yourself your home town your family your name or anything else associated with you Tell your group and write it down.
Standards-based grading Scored on standards, not points The more standards you meet, the higher your final grade
Meeting the Standards Last assessment matters Don’t blow off early assessments: learn! If lots of folks miss a standard, I’ll re-quiz If you personally miss a standard: Work some more problems See me for a re-assessment I want you to succeed.
Quizzes In lecture May be announced or unannounced Assess on standards (no numeric score)
Exams On-line Moodle course management system Thursday Evenings Awarded points aren’t directly significant Final Last opportunity to make up missed standards Evaluate on standards
Textbook • Textbook; Hewitt, Conceptual Physics 11 ed. (req.)with Practicing Physics workbook • Lab manual: photocopy(also online)
Lab Physical Science building room 137 (north hallway) Labs begin TODAY Hours: TW 1:10–3:00 TA’s: • We’re still working on that
Discussion Section Times and locations vary Discussions begin TODAY Hours: T 11:00–11:50 3:10–4:00R 3:10–4:00 TAs: TBA
PollEverywhere Poll input by text message, web site, or Twitter. • Which is best? • A good thing. • A bad thing.
Read the Textbook • Read before class • Study after • Reading guides available on web site
Prepare for Lab • Read manual before lab • Lab manual on class web site • Pre-labs due in lab
Use Web Resources • Class web site • www.barransclass.com/phys1050 • Syllabus, schedule, lab manual, reading guides, highlights, PowerPoints,etc. • Moodle • CRTeacher2.com • Practice problems: practice all you want • Register on-line immediately
Visit Me Physical Science building room 110 (south hallway) 33% moreFree! Hours: MWF 3:10–4:00 PMR 11:00–11:50 AM or by appointment or come in if the door is open
Absence Policy • Contact me beforehand if foreseen • Contact me ASAP for emergencies • Arrange make-up within one week of return • No make-up or re-take for items missed without approval • Labs pro-rated if make-up impractical
Pre-Vet, Pre-Dent • Many grad schools require PHYS 1110 • UW grants credit for only one of PHYS 1050, 1110, 1210 • FWIW: Students taking 1110 after 1050 tend to do very well • I provide a guarantee
The Science of Physics The fundamental quantities
Indefinable Fundamentals • Distance • Mass • Electric charge • Time
Distance • Defined circularly with length • Length: the distance between specified locations • Distance: the length of a line segment joining two points American Heritage Dictionary, 1981.
Mass 6. The measure of a body’s response to acceleration. The mass of a body is different from but proportional to its weight, is independent of the body’s position but dependent on its motion with respect to other bodies, and may be expressed in mass units, such as kilograms or slugs, or corresponding energy units, by means of the mass-energy relationship of the special theory of relativity. American Heritage Dictionary, 1981.
Charge 14a. The intrinsic property of matter responsible for all electric phenomena, in particular for the force of the electromagnetic interaction,occurring in two forms arbitrarily designated negative and positive. American Heritage Dictionary, 1981.
Time • A nonspatial continuum in which events occur in apparently irreversible succession from the past to the present to the future. • An interval separating two points on this continuum, measured essentially by selecting a regularly occurring event, such as the sunrise, and counting the number of occurrences during the interval’s duration. American Heritage Dictionary, 1981.
Fundamental Units Quantity Unit Distance meter (m) Mass kilogram (kg) Charge coulomb (C) Time second (s) SI (International System) or MKS units
Fundamental Units • All units we will encounter are defined in terms of the fundamental m, kg, C, and s.
Working with Units Math makes sense
Eat a live bullfrog first thing in the morning… …and nothing worse will happen to you for the rest of the day!
6 x = 3 x/y 2 y 6 C = 3 C/s 2 s Do math with units • Unit labels can be treated like any variable in algebra. Add them! 3 x + 4 x = 7 x 3 s + 4 s = 7 s Divide them! Multiply them! (3a)(4b) = 12 ab (3 m/s)(4 s) = 12 m
Compound Units • Areas • Volumes • Accumulated effects • Effects of population Represent:
Compound Units a Area = ab b
Compound Units Effort = (3 w) (4 h) = 12 (w)(h) = 12 worker·hours 3workers 4 h
Ratio Units • Rates of change • Intrinsic properties Represent:
10 0.75 y 8 mass (kg) 6 5.4 kg 5.4 kg 4 0.75 y 2 0 0 1 time (y) Ratio Units A baby has a mass of 3.2 kg at birth and 8.6 kg 9 months later. What is its average annual growth rate during this time? slope = = 7.2 kg/y
39.37 in 1 m 1 = 1 = 1 m 39.37 in 72 = m 39.37 1 m = 72 in · 39.37 in Manipulating Units • Conversions 39.37 in = 1 m equality conversion factors 72 in = 72 in · 1 = 1.829 m
Group Work • 1 mi = 5280 ft1 yd = 3 ft Set up the conversion 2 mi to yd. • 1 mi = 5280 ft1 ft = 12 in1 m = 39.37 in1 h = 3600 sSet up the conversion 75 mi/h to m/s.
Reading for Next Time • Distance, velocity, and acceleration: how physics describes motion • Keep in mind the relations between different quantities
Right away • Go to your lab session this week. • Go to your discussion session this week. • Get a Moodle account. • Join this course on Moodle. • Complete the assigned reading.