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Some Information
Class website:http://people.virginia.edu/∼xz5y/PHYS201/
All course information is on the aboveWebsite
Go to UVaCollab under Resources after everylecture to look at the notes.
Let’s go through some things
Physics 201 – p. 2/21
Some Information
Class website:http://people.virginia.edu/∼xz5y/PHYS201/
All course information is on the aboveWebsite
Go to UVaCollab under Resources after everylecture to look at the notes.
Let’s go through some things
Physics 201 – p. 2/21
Some Information
Class website:http://people.virginia.edu/∼xz5y/PHYS201/
All course information is on the aboveWebsite
Go to UVaCollab under Resources after everylecture to look at the notes.
Let’s go through some things
Physics 201 – p. 2/21
Some Information
Class website:http://people.virginia.edu/∼xz5y/PHYS201/
All course information is on the aboveWebsite
Go to UVaCollab under Resources after everylecture to look at the notes.
Let’s go through some things
Physics 201 – p. 2/21
What you need for the course
Textbook: Physics, 4th Edition by Walker, andMastering Physics
iClicker: Important to understand the policy(class website) for using this unit.
Physics 201 – p. 3/21
What you need for the course
Textbook: Physics, 4th Edition by Walker, andMastering Physics
iClicker: Important to understand the policy(class website) for using this unit.
Physics 201 – p. 3/21
Course Objectives:
To learn and understand the physical world
How? Problem Solving and ConceptualUnderstanding.
How to achieve that?LecturesReading and Conceptual quizzes in classHomeworksDiscussion Section Quizzes
Physics 201 – p. 4/21
Course Objectives:
To learn and understand the physical world
How? Problem Solving and ConceptualUnderstanding.
How to achieve that?LecturesReading and Conceptual quizzes in classHomeworksDiscussion Section Quizzes
Physics 201 – p. 4/21
Course Objectives:
To learn and understand the physical world
How? Problem Solving and ConceptualUnderstanding.
How to achieve that?LecturesReading and Conceptual quizzes in classHomeworksDiscussion Section Quizzes
Physics 201 – p. 4/21
Homework assignments
Homeworks will be found and submitted onMasteringPhysics. Register onMasteringPhysics now!
Check carefully the due date and time.
Look at the class homepage for policiesconcerning late homeworks.
Physics 201 – p. 5/21
Homework assignments
Homeworks will be found and submitted onMasteringPhysics. Register onMasteringPhysics now!
Check carefully the due date and time.
Look at the class homepage for policiesconcerning late homeworks.
Physics 201 – p. 5/21
Homework assignments
Homeworks will be found and submitted onMasteringPhysics. Register onMasteringPhysics now!
Check carefully the due date and time.
Look at the class homepage for policiesconcerning late homeworks.
Physics 201 – p. 5/21
Behavior to avoid in class
Surf the Web
Private chats
Entering and leaving class at inappropriatetimes
Loud snoring (with nightmares)
Physics 201 – p. 6/21
Behavior to avoid in class
Surf the Web
Private chats
Entering and leaving class at inappropriatetimes
Loud snoring (with nightmares)
Physics 201 – p. 6/21
Behavior to avoid in class
Surf the Web
Private chats
Entering and leaving class at inappropriatetimes
Loud snoring (with nightmares)
Physics 201 – p. 6/21
Behavior to avoid in class
Surf the Web
Private chats
Entering and leaving class at inappropriatetimes
Loud snoring (with nightmares)
Physics 201 – p. 6/21
How to learn from the Textbook
Work out the conceptual questions at the endof each chapter
Work out extra problems (call beyond duty)
Learn the strategy of problem solving fromProblem-Solving Summaries
Physics 201 – p. 7/21
How to learn from the Textbook
Work out the conceptual questions at the endof each chapter
Work out extra problems (call beyond duty)
Learn the strategy of problem solving fromProblem-Solving Summaries
Physics 201 – p. 7/21
How to learn from the Textbook
Work out the conceptual questions at the endof each chapter
Work out extra problems (call beyond duty)
Learn the strategy of problem solving fromProblem-Solving Summaries
Physics 201 – p. 7/21
Length, Mass and Time: SI units
Unit of length: meter (m)One ten-millionth of the distance betweenthe North Pole and the Equator, two markson a platinum-iridium rod in Paris.Distance traveled by light in vacuum in1/299,792,458 of a second.1 inch = 2.54 cm; 3.28 ft = 1 m
Physics 201 – p. 8/21
Length, Mass and Time: SI units
Unit of mass:kilogram (kg)Kilogram = mass of platinum-iridiumcylinder kept outside Paris.Mass (intrinsic property) 6= Weight (forcedue to gravity)
Physics 201 – p. 9/21
Length, Mass and Time: SI units
Unit of time: second (s)Earth rotation, etc...Most accurate: Atomic Clock (Cesium-133)
Physics 201 – p. 10/21
Dimensional Analysis
Apples 6= Oranges
Position versus time: Is x = x0 + vt2 correct?x: distance [L]v: velocity (distance/time) [L]/[T]vt2: ([L]/[T ]) × [T ]2 = [L] × [T ] ⇒ WrongDimension
Correct dependence: x = x0 + αvt. α: adimensionless constant determined byphysics.Let’s check: [L] = [L] + ([L]/[T])[T] Correct!
Physics 201 – p. 15/21
Dimensional Analysis
Apples 6= Oranges
Position versus time: Is x = x0 + vt2 correct?x: distance [L]v: velocity (distance/time) [L]/[T]vt2: ([L]/[T ]) × [T ]2 = [L] × [T ] ⇒ WrongDimension
Correct dependence: x = x0 + αvt. α: adimensionless constant determined byphysics.Let’s check: [L] = [L] + ([L]/[T])[T] Correct!
Physics 201 – p. 15/21
Significant Figures
Significant Figure = Number of digits knownwith certainty
Example: x = 2.5m ⇒ x is known to twosignificant figures.
Multiplication or Division: a × b = c or a/b = c⇒ number of sig fig for c = number of sig figof the least accurate of a or b. Same for morecomplicated expressions.
Addition or Subtraction: a + b = c or a − b = c⇒ number of decimal places for c = number ofdecimal places of the least accurate of a or b
Physics 201 – p. 16/21
Significant Figures
Significant Figure = Number of digits knownwith certainty
Example: x = 2.5m ⇒ x is known to twosignificant figures.
Multiplication or Division: a × b = c or a/b = c⇒ number of sig fig for c = number of sig figof the least accurate of a or b. Same for morecomplicated expressions.
Addition or Subtraction: a + b = c or a − b = c⇒ number of decimal places for c = number ofdecimal places of the least accurate of a or b
Physics 201 – p. 16/21
Significant Figures
Significant Figure = Number of digits knownwith certainty
Example: x = 2.5m ⇒ x is known to twosignificant figures.
Multiplication or Division: a × b = c or a/b = c⇒ number of sig fig for c = number of sig figof the least accurate of a or b. Same for morecomplicated expressions.
Addition or Subtraction: a + b = c or a − b = c⇒ number of decimal places for c = number ofdecimal places of the least accurate of a or b
Physics 201 – p. 16/21
Significant Figures
Significant Figure = Number of digits knownwith certainty
Example: x = 2.5m ⇒ x is known to twosignificant figures.
Multiplication or Division: a × b = c or a/b = c⇒ number of sig fig for c = number of sig figof the least accurate of a or b. Same for morecomplicated expressions.
Addition or Subtraction: a + b = c or a − b = c⇒ number of decimal places for c = number ofdecimal places of the least accurate of a or b
Physics 201 – p. 16/21
Example
The Coyote steadily sneaks upon theRoadrunner with a constant speed of 1.2 m/s.
How much distance has he covered after 5.35 s?1) 1.2m/s × 5.4s = 6.48m2) 1.2m/s × 5.4s = 6.5m3) 1.2m/s × 5.35s = 6.42m ≈ 6.4m
(1): Incorrect number of Sig Fig in theanswer; Round-off error in the time
(2): Correct number of Sig Fig in the answerbut round-off error in the time
(3): Everything is done correctly
Physics 201 – p. 17/21
Example
The Coyote steadily sneaks upon theRoadrunner with a constant speed of 1.2 m/s.
How much distance has he covered after 5.35 s?1) 1.2m/s × 5.4s = 6.48m2) 1.2m/s × 5.4s = 6.5m3) 1.2m/s × 5.35s = 6.42m ≈ 6.4m
(1): Incorrect number of Sig Fig in theanswer; Round-off error in the time
(2): Correct number of Sig Fig in the answerbut round-off error in the time
(3): Everything is done correctly
Physics 201 – p. 17/21
Example
The Coyote steadily sneaks upon theRoadrunner with a constant speed of 1.2 m/s.
How much distance has he covered after 5.35 s?1) 1.2m/s × 5.4s = 6.48m2) 1.2m/s × 5.4s = 6.5m3) 1.2m/s × 5.35s = 6.42m ≈ 6.4m
(1): Incorrect number of Sig Fig in theanswer; Round-off error in the time
(2): Correct number of Sig Fig in the answerbut round-off error in the time
(3): Everything is done correctlyPhysics 201 – p. 17/21
Scientific Notation
Example: Speed of Light = 299, 792, 458 m/s.Known to 9 sig figs.
It can be written as 2.99792458 × 108 m/s.
One can write it as 3.0 × 108 m/s if it is knownto 2 sig figs.
Physics 201 – p. 18/21
Scientific Notation
Example: Speed of Light = 299, 792, 458 m/s.Known to 9 sig figs.
It can be written as 2.99792458 × 108 m/s.
One can write it as 3.0 × 108 m/s if it is knownto 2 sig figs.
Physics 201 – p. 18/21
Scientific Notation
Example: Speed of Light = 299, 792, 458 m/s.Known to 9 sig figs.
It can be written as 2.99792458 × 108 m/s.
One can write it as 3.0 × 108 m/s if it is knownto 2 sig figs.
Physics 201 – p. 18/21
Change of unit
Example: Kareem Abdul-Jabar is 7-foot-2. Howtall is he in meters?Answer: 1) 2 in = 1/6 ft; 2)7 − foot − 2 ≈ 7.16ft = 7.16ft/3.28ft = 2.18m.
Physics 201 – p. 19/21
Order-of-magnitude estimates
How many grains of rice are there in the jar lyingon that table in class?
Physics 201 – p. 20/21
Problem Solving
Read the problem carefully
Sketch the system
Visualize the physical process
Find a strategy
Find the appropriate equations
Solve the equations
Check your answer
Limits and special cases
Physics 201 – p. 21/21
Problem Solving
Read the problem carefully
Sketch the system
Visualize the physical process
Find a strategy
Find the appropriate equations
Solve the equations
Check your answer
Limits and special cases
Physics 201 – p. 21/21
Problem Solving
Read the problem carefully
Sketch the system
Visualize the physical process
Find a strategy
Find the appropriate equations
Solve the equations
Check your answer
Limits and special cases
Physics 201 – p. 21/21
Problem Solving
Read the problem carefully
Sketch the system
Visualize the physical process
Find a strategy
Find the appropriate equations
Solve the equations
Check your answer
Limits and special cases
Physics 201 – p. 21/21
Problem Solving
Read the problem carefully
Sketch the system
Visualize the physical process
Find a strategy
Find the appropriate equations
Solve the equations
Check your answer
Limits and special cases
Physics 201 – p. 21/21
Problem Solving
Read the problem carefully
Sketch the system
Visualize the physical process
Find a strategy
Find the appropriate equations
Solve the equations
Check your answer
Limits and special cases
Physics 201 – p. 21/21
Problem Solving
Read the problem carefully
Sketch the system
Visualize the physical process
Find a strategy
Find the appropriate equations
Solve the equations
Check your answer
Limits and special cases
Physics 201 – p. 21/21