Werner Ens 518 Allen Office Hours: Monday pm (or by appointment)

Werner Ens 518 Allen Office Hours: Monday pm (or by appointment) My PowerPoint lecture notes available on-line (Complete lecture notes prepared last year by Professor Birchall are available at the course web site)

Quiz 1.Which arrows correctly represent acceleration? (a)(b)(c) (d) (e)

Quiz 2. Which is the trajectory after the line is cut? (a) (b) (c) (d)

Quiz 3. What happens to an astronaut if his tether to an orbiting space station is cut? (a) Stays with space station (b) Falls behind in orbit (c) Falls to earth (d) Lost in space (moves away) (e) Remains stationary with respect to the sun

Quiz 4. What happens if an astronaut releases a ball while standing on the moon? (a) It falls to the ground (moon) (b) It rises (c) It stays where it is released (d) Moves horizontally (moon’s horizon)

Quiz solutions 1.Which arrows correctly represent acceleration? (a)(b)(c) (d) (e)

Quiz solutions 2. Which is the trajectory after the line is cut? (a) (b) (c) (d)

Quiz solutions 3. What happens to an astronaut if his tether to an orbiting space station is cut? (a) Stays with space station (b) Falls behind in orbit (c) Falls to earth (d) Lost in space (moves away) (e) Remains stationary with respect to the sun

Quiz solutions 4. What happens if an astronaut releases a ball while standing on the moon? (a) It stays where it is (b) It rises (c) It falls to the ground (moon) (d) Moves horizontally (moon’s horizon)

Quiz solutions 1 d, 2 b, 3 a, 4 c

Chapter 1 Introduction Mathematical Concepts

1) Representation of physical quantities Arithmetic is abstract: = 5 A physical quantity (distance) requires comparison to a standard: L = 10 is meaningless m 10 m A physical quantity is an algebraic product of a number and a unit: L = 10 m

2) Units combine algebraically; Dimensional Analysis

Example: Vector Addition Jogger runs 145 m 20.0º East of North –Displacement vector A Then 105 m 35.0º South of East –Displacement vector B Find resultant displacement C=A+B 20º x (E) y (N) 35º Step 0: Draw a picture & organize data

Example: Vector Addition 20º x (E) y (N) Step 1: Convert to component representation

Example: Vector Addition x (E) y (N) 35º Step 1: Convert to component representation

Example: Vector Addition Step 2: Sum components 20º x (E) y (N) 35º

Example: Vector Addition Step 3: Convert result to geometric representation (magnitude, direction) x (E) y (N)

Example: Vector Addition Step 3: Convert to geometric representation (magnitude, direction) x (E) y (N)

Example: Vector Addition Step 3: Convert to geometric representation (magnitude, direction) x (E) y (N)