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PHY 2048C General Physics I with lab Spring 2011 CRNs 11154, 11161 & 11165. Dr. Derrick Boucher Assoc. Prof. of Physics. Outline for Lecture 1. Syllabus Course Resources tour LON-CAPA tour Standard Lecture Format PRS clickers Chapter 1 Chapter 2. Course Resources. Dr. Boucher’s website
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PHY 2048CGeneral Physics I with labSpring 2011CRNs 11154, 11161 & 11165 Dr. Derrick Boucher Assoc. Prof. of Physics
Outline for Lecture 1 • Syllabus • Course Resources tour • LON-CAPA tour • Standard Lecture Format • PRS clickers • Chapter 1 • Chapter 2
Course Resources Dr. Boucher’s website http://ruby.fgcu.edu/courses/dboucher/ Syllabus http://ruby.fgcu.edu/courses/dboucher/p2048%20syllabus%20s11%20boucher.pdf Schedules http://ruby.fgcu.edu/courses/dboucher/Spring_2011_GPschedule.pdf
Course Resources, cont. Lab Resources Schedule: http://ruby.fgcu.edu/courses/dboucher/lab_schedule_spring_2011.htm Procedures, other helpful files: http://ruby.fgcu.edu/courses/dboucher/lab%20resources.htm
Course Resources, cont. • Equation sheet (still being prepared) • All the equations you’ll need for the course • Conversion factors and constants • Provided for every exam • Useful for study • So, what do you need to know? • Mensuration formulas (areas, volumes, etc.) • Geometry, trig and calculus • Metric prefixes giga, mega, kilo, centi, milli, micro, nano
LON-CAPA Our online homework system Free to use Locally administered (problems get solved!) Allows discussion among students, instructor Take a look: http://orion.cas.fgcu.edu/adm/roles
Standard Lecture Format Announcements, glimpse at schedules Handouts PRS clicker logins (attendance) Old business (handing graded items back, reviewing homework, etc.) (Maybe) quiz on past material and/or current reading New concepts and equations (kicking the tires) Example Problem(s) Repeat 6 & 7 as necessary…
Chapter 1 and 2 Practice Problems Chap 1: 1, 3, 7, 13, 15, 19, 23, 25, 27, 29, 37, 41 Chap 2: 3, 7, 9, 11, 31, 57, 63, 69, 71 Unless otherwise indicated, all practice material is from the “Exercises and Problems” section at the end of the chapter. (Not “Questions.”)
Chapter 1 • READ IT • Review and learn as necessary • Some highlights follow
The Particle Model • For simple motion we can consider the object as if it were just a single point, without size or shape. • All the mass is concentrated at that point. • A particle has no size, no shape, and no distinction between top and bottom or between front and back.
Making a Motion Diagram Simplify a “movie” in one diagram tree Equally spaced points represents constant speed; the car travels equal distances in equal times Position at equal time intervals
Average Speed, Average Velocity To quantify an object’s fastness or slowness, we define a ratio as follows: Average speed does not include information about direction of motion. Average velocity does include direction. The average velocity of an object during a time interval Δt, in which the object undergoes a displacement Δr, is the vector In one dimension, direction is either + or – (it’s up to you which real direction + or – actually means). Then, r is x or y.
Instantaneous Velocity Average velocity is calculated over an extended period of time. As ∆t gets smaller and smaller, we can think of the velocity at a particular instant in time. This is especially useful when velocity changes. Graphically, v is the slope of a line tangent to the position vs. time curve. You may (should) recognize this as the derivative! Notation in text: “s” means x, y or z…whatever direction you are dealing with
Example problem Chapter 2 #6 (p. 65)
PRS Clicker Questions
Sample question; Dr. Boucher’s favorite color is, Blue Green Chartreuse Red None. Dr. Boucher sees in black-and-white.
At the turning point of an object, the instantaneous velocity is zero. the acceleration is zero. both A and B are true. neither A nor B is true. This topic was not covered in this chapter.
REDO (after discussion) At the turning point of an object, the instantaneous velocity is zero. the acceleration is zero. both A and B are true. neither A nor B is true. This topic was not covered in this chapter.
Which position-versus-time graph represents the motion shown in the motion diagram?
Which velocity-versus-time graph goes with the position-versus-time graph on the left?
REDO Which velocity-versus-time graph goes with the position-versus-time graph on the left?
Average acceleration To quantify an object’s change in motion, we define acceleration: Average acceleration should include direction. The average velocity of an object during a time interval Δtis a vector. In one dimension (chapter 2), direction is either + or – (it’s up to you which real direction + or – actually means). Then, “s” is x or y.
Example problem Chapter 2 #8 (p. 65)
“s” means x, y or z…whatever direction you are dealing with 1604 Galileo experiments with falling bodies, especially ones “falling” down an inclined plane. 1607 Finally formulates the equations you see above.
“kinematics” • Using the kinematic (Galileo’s) equations: • They only apply AFTER motion has begun • Do not worry about the details of HOW something got into motion • As soon as conditions change (a new force appears, an old force disappears, a collision…) you need to apply a new set of equations
Example problem Chapter 2 #14 (p. 66)
Example problem Chapter 2 #66 (p. 70)
Free Fall • Free fall technically means that gravity is the only force acting on the object • The gravitational force is constant • Therefore, so is the acceleration, so Galileo’s equations apply! • a = “g” = 9.8 m/s2 near the Earth’s surface IMPORTANT: g = 9.8 but a can be + 9.8 OR −9.8 depending on which way you define down to be. It is customary, and smart, to use − for down!
A 1-pound block and a 100-pound block are placed side by side at the top of a frictionless hill. Each is given a very light tap to begin their race to the bottom of the hill. In the absence of air resistance the 1-pound block wins the race. the 100-pound block wins the race. the two blocks end in a tie. there’s not enough information to determine which block wins the race.
Example problem Chapter 2 #16 (p. 66)
Example problem Chapter 2 inclined plane (not in text)
Calculus and Motion Read the material in chapter 2 and review your calculus as necessary. For now, I will focus on using derivatives more than integrals.
Example problem Chapter 2 derivatives and motion (not in text)