Physics 214 Physics of everyday phenomena Professor David

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Physics 214 Physics of everyday phenomena Professor David H Miller Office room 376 millerdh@purdue.

Physics 214 Physics of everyday phenomena Professor David H Miller Office room 376 millerdh@purdue. edu Course Web site http: //www. physics. purdue. edu/academic_programs/courses/phys 214 / Undergrad Office Room 144, Questions, Handouts Announcements, Syllabus, schedule, Lecture notes, practice exams v. Lists lecture schedule v. Times and place of the two evening exams v. Deadlines for Homework and Quizzes v. Use of the I clicker v. Useful information 11/1/2021 Physics 214 Fall 2011 1

This Week • Introduction Syllabus, CHIP, Office hours • Grading Exams, I clicker, pre

This Week • Introduction Syllabus, CHIP, Office hours • Grading Exams, I clicker, pre lecture quiz • General Who am I, our Universe • Lecture Ch 1, 2 Straight line motion • Tsunamis 11/1/2021 Physics 214 Fall 2011 2

The Book v. Book : Physics of Everyday Phenomena 5 th, 6 th or

The Book v. Book : Physics of Everyday Phenomena 5 th, 6 th or 7 th edition v. OVERVIEW v. OUTLINE v. CHAPTER MATERIAL v. SUMMARY v. QUESTIONS/EXERCISES v. HOME EXPERIMENTS AND OBSERVATIONS 11/1/2021 Physics 214 Fall 2011 3

Course Outline v The lecture schedule and reading assignments are shown in the syllabus.

Course Outline v The lecture schedule and reading assignments are shown in the syllabus. In practice this might change but we will always be ahead of the homework. v I will do many demonstrations in class and questions on these will be on the exams v I encourage interaction and will leave plenty of time for questions. v There will be two one hour evening exams and a two hour final v We will be using I clickers for in class quizzes 11/1/2021 Physics 214 Fall 2011 4

Reading and Problems It is very important that you v Read all the chapter

Reading and Problems It is very important that you v Read all the chapter material v work some questions, exercises and problems v Answers are in appendix d for: Questions Every 6 th question starting with #3 Exercises Odd numbered Problems Odd numbered v Lectures will be posted on the Web weekly 11/1/2021 Physics 214 Fall 2011 5

CHIP (Computerized Homework in Physics) There are 28 Homework assignments. First one is due

CHIP (Computerized Homework in Physics) There are 28 Homework assignments. First one is due by noon Friday August 26 th There are 32 pre lecture quizzes First one is due by 8. 30 am Wed August 24 th IMPORTANT Read the QUICK GUIDE TO CHIP handout and login to the CHIP site today and make sure your Career ID and password work. There is a much longer guide to CHIP that you can access from the course home page. You must also register the serial number of your I Clicker in the student grade book of CHIP It is very unlikely that there any errors in CHIP if it will not accept your answer then you have made an error. Most common errors are Wrong answer, Significant figures, Wrong sign 11/1/2021 Physics 214 Fall 2011 6

Getting Help There will be a TA and I will announce location and office

Getting Help There will be a TA and I will announce location and office hours. There are three levels of help • See the TA during office hours or email the TA • Send questions by email to millerdh@purdue. edu • see me after lecture and make an appointment There will be a 2 hour evening help session before each exam. 11/1/2021 Physics 214 Fall 2011 7

Plus Minus Grading We will be using the new Plus Minus grading system 11/1/2021

Plus Minus Grading We will be using the new Plus Minus grading system 11/1/2021 A+, A 4. 0 A- 3. 7 B+ 3. 3 B 3. 0 B- 2. 7 C+ 2. 3 C 2. 0 C 1. 7 D+ 1. 3 D 1. 0 D 0. 7 E, F, WF, EF, IF Physics 214 Fall 2011 0. 0 8

Who am I Originally from England I’m an experimentalist in High Energy or Elementary

Who am I Originally from England I’m an experimentalist in High Energy or Elementary Particle Physics trying to find/understand v The physical laws which govern the Universe v The fundamental building blocks of all matter v The evolution of the Universe from the Big Bang to the present day, 13. 6 billion years later We use Ø Particle accelerators which produce collisions with energy densities the same as a billionth of a second after the big bang. 11/1/2021 Physics 214 Fall 2011 9

Large Hadron Collider The worlds highest energy collisions in Geneva, Switzerland. 18 miles in

Large Hadron Collider The worlds highest energy collisions in Geneva, Switzerland. 18 miles in circumference with 800, 000 liters of liquid Helium (the coldest place in the entire Universe) 11/1/2021 Physics 214 Fall 2011 10

This week Our Universe • Our World • How do we measure quantities •

This week Our Universe • Our World • How do we measure quantities • Describing moving objects • Tsunami’s • 11/1/2021 Physics 214 Fall 2011 11

What is Physics is the study and understanding of all the physical phenomena v

What is Physics is the study and understanding of all the physical phenomena v That we see in our everyday life v At very small distances, atoms, nuclei, quarks… v At extreme energies – Big Bang v At extreme velocities - relativity v On earth and throughout the Universe and back in time to 13. 7 billion years ago – Hubble, Cobe, WMAP v We are able to explore and understand the whole Universe from a billionth of a second after the big bang to today and also predict the future 11/1/2021 Physics 214 Fall 2011 12

Experiment and theory v. Our knowledge is based on experiments which are reproducible. v

Experiment and theory v. Our knowledge is based on experiments which are reproducible. v We develop mathematical theories which agree with experiment and generally predict new phenomena. v. Experimentalists are not constrained by theory and continue to examine our Universe from 10 -17 m to 13 billion light years and from t = “ 0” to 13. 7 billion years later. vany new theory must agree with all previous experimental observations. v. A theory is a mathematical consistent framework for the interpretation of all accumulated knowledge. v. It is like looking at a partially painted picture and determining what the finished picture would depict. 11/1/2021 Physics 214 Fall 2011 13

Physics of the Universe §We only have one planet §We only have one Universe

Physics of the Universe §We only have one planet §We only have one Universe §Current understanding is always based on the simplest explanation that fits the facts (no aliens!!) §Experimental measurements always have errors §Forefront science is very difficult and incorrect results do occur which are then corrected 11/1/2021 Physics 214 Fall 2011 14

Where are we? Light Year: the distance that light travels in one year (9.

Where are we? Light Year: the distance that light travels in one year (9. 46 x 1017 cm). 186282 x 365. 242 x 24 x 3600 x 5280 x 30. 48 1. 86282 x 105 x 3. 65242 x 102 x 24 x 3. 6 x 103 x 5. 280 x 103 x 30. 48 The nearest star (other than the sun) is 4. 3 light years away. Our Galaxy (the Milky Way) with 100 billion stars is about 100, 000 light years in diameter. Number of stars in the Universe is ~ 1028 11/1/2021 Physics 214 Fall 2011 15

Framework Underlying principles §Physics is the same everywhere §Fundamental constants and physical laws have

Framework Underlying principles §Physics is the same everywhere §Fundamental constants and physical laws have not changed over the age of the Universe Observations §We can create conditions in the laboratory that are the same as those which existed a billionth of a second after the big bang. §We understand the physics which led to the distribution and type of matter in the Universe §We can look back over 13 billion years and see the evolution of the Universe 11/1/2021 Physics 214 Fall 2011 16

Forces and Particles Fundamental forces are what has shaped the Universe and are responsible

Forces and Particles Fundamental forces are what has shaped the Universe and are responsible for all the phenomena we see in our everyday life. There are only 5 forces v Strong Force – holds the protons and neutrons of the nucleus together v Weak Force – responsible for radioactive decay v Electromagnetic force – Holds electrons in atoms, electrical currents, magnetism, light v Gravitation - Attractive force between objects, solar system v Dark Energy – mysterious force expanding space 11/1/2021 Physics 214 Fall 2011 17

Structure and Forces Gravitation F Strong Force Solar system galaxies objects falling Electric charge

Structure and Forces Gravitation F Strong Force Solar system galaxies objects falling Electric charge F F F everything not gravity biology photosynthesis Weak Force cars, planes + electron Common carrier of electric charge and electric current is the electron 11/1/2021 Neutron Proton Radioactive decay Physics 214 Fall 2011 18

Building blocks Quarks – up, down, strange, charm, beauty, top Leptons - electron, muon,

Building blocks Quarks – up, down, strange, charm, beauty, top Leptons - electron, muon, tau, 3 neutrinos Force carriers – γ, g, W, Z Missing pieces Building blocks – Higgs, supersymmetry… Questions – Dark energy, dark matter…. . Speculation – parallel universes, extra dimensions. . 11/1/2021 Physics 214 Fall 2011 19

The Universe 11/1/2021 Physics 214 Fall 2011 20

The Universe 11/1/2021 Physics 214 Fall 2011 20

Large scale structure 11/1/2021 Physics 214 Fall 2011 21

Large scale structure 11/1/2021 Physics 214 Fall 2011 21

The Universe at 300, 000 years 2. 70 K relic radiation from 300, 000

The Universe at 300, 000 years 2. 70 K relic radiation from 300, 000 years after the big bang 11/1/2021 Physics 214 Fall 2011 22

Fundamentals As we observe the world around us we need to describe it in

Fundamentals As we observe the world around us we need to describe it in the language of mathematics. We need the fundamental quantities v. Length (distance) v. Time v. Coordinate system (reference point, direction, clock) v. Mass ( so much of something) 11/1/2021 Physics 214 Fall 2011 23

Units and definitions Over the few thousand years of science there have been many

Units and definitions Over the few thousand years of science there have been many systems of units but the system of choice is the SI system http: //unicon. netian. com/unitsys_e. html SI Length – hand, foot, mile, … meter Time – sundial, water clock, second Direction – north, south, east, west cartesian Mass – pound, ton, gram… kilogram Volume – peck, bushel, cup … cubic meter Area - acre, square mile, hectare square meter 11/1/2021 Physics 214 Fall 2011 24

Consistency v We always need to use consistent units so that in equations such

Consistency v We always need to use consistent units so that in equations such as A = B + C the quantities A, B, C have the same units. v We may need to convert units to be consistent v Your answers to problems must also have units. v You do not always have to convert to SI units. For example if you travel 60 miles in two hours then your average speed is 30 miles per hour and you do not convert to meters/second unless you are specifically asked to do so. 11/1/2021 Physics 214 Fall 2011 25

Conversions, prefixes and scientific notation giga 1, 000, 000 109 billion 1 in 2.

Conversions, prefixes and scientific notation giga 1, 000, 000 109 billion 1 in 2. 54 cm mega 1, 000 106 million 1 cm 0. 394 in kilo 1, 000 103 thousand 1 ft 30. 5 cm centi 1/100 0. 01 10 -2 hundredth 1 m 39. 4 in milli 1/1000 0. 001 10 -3 thousandth 1 km 0. 621 mi 5280 ft 1. 609 km 1 lb 0. 4536 kg g =9. 8 1 kg 2. 205 lbs g=9. 8 micro 1/1, 000 1/106 10 -6 millionth nano 1/1, 000, 000 1/109 10 -9 billionth 3. 281 ft Appendix b 11/1/2021 Physics 214 Fall 2011 26

Average speed = distance/time s = d/t = 260/5 = 52 mph Units meters/second

Average speed = distance/time s = d/t = 260/5 = 52 mph Units meters/second kilometers/second miles/hour feet/second Average speed is a positive number 52 mph = 52 x 5280/3600 = 76. 26666666 = 76. 27 feet/sec (60 mph = 88 ft/sec) 11/1/2021 Physics 214 Fall 2011 27

Instantaneous speed is what you see on your speedometer. This is the average speed

Instantaneous speed is what you see on your speedometer. This is the average speed for a very short time interval s = d/Δt We can plot speed versus time and obtain a graph which has all the information for the journey moviecar 11/1/2021 Physics 214 Fall 2011 28

Vector quantities In addition to knowing average speed or instantaneous speed we need to

Vector quantities In addition to knowing average speed or instantaneous speed we need to know the direction. The quantity giving both speed and direction is the velocity. Velocity is an example of a vector quantity and is represented in a “picture” by an arrow giving the direction and the length of the arrow proportional to the magnitude. Velocity Acceleration Force momentum Appendix c To specify direction we need a coordinate system 11/1/2021 Physics 214 Fall 2011 29

Coordinate systems We live in a three dimensional world so the general coordinate system

Coordinate systems We live in a three dimensional world so the general coordinate system uses three axes at right angles x, y, z. We will use coordinate systems in one or two dimensions - +x N W y + E - x - S 11/1/2021 + Physics 214 Fall 2011 30

The earth as a coordinate system and Maps We live on a sphere but

The earth as a coordinate system and Maps We live on a sphere but most maps are flat and this increases the apparent size of countries as one moves further from the equator 1 nautical mile = 1/21600 of the circumference of the earth at the equator 1 knot = 1 nautical mile per hour 1. 1508 miles/hour 1 kilometer = 1/10, 000 the distance from the North Pole to the equator passing through Paris 11/1/2021 Physics 214 Fall 2011 31

Motion in a straight line - + x d d is the distance from

Motion in a straight line - + x d d is the distance from the start point it is NOT necessarily the total distance traveled 2 3 4 1 1 Constant velocity + 2 Stopped 3 Constant velocity + 4 Constant velocity 11/1/2021 Physics 214 Fall 2011 32

Acceleration A change in velocity is called acceleration a = change in velocity/elapsed time

Acceleration A change in velocity is called acceleration a = change in velocity/elapsed time a = Δv/t Average acceleration t is “large” Instantaneous acceleration a = Δv/ Δt Acceleration is a vector with direction defined by Δv units are length/(time x time) meters/sec miles/hour feet/sec Δv = vfinal – vinitial can be + or – 11/1/2021 Physics 214 Fall 2011 33

Straight line motion Constant acceleration or v = v 0 + at (definition of

Straight line motion Constant acceleration or v = v 0 + at (definition of acceleration) “red area” = vΔt = distance traveled in Δt d = v 0 t + 1/2 Δv t but since a = Δv/t d = v 0 t + 1/2 at 2 (d is distance from start) d = 1/2(v + v 0) t (average speed times t) http: //www. physics. purdue. edu/class/applets/phe/acceleration. htm 11/1/2021 Physics 214 Fall 2011 34

General case of acceleration Acceleration occurs when the velocity changes in magnitude or direction

General case of acceleration Acceleration occurs when the velocity changes in magnitude or direction or both. In the first example shown if the magnitude of v does not change we have uniform circular motion and the acceleration vector points toward the center of the circle. a 11/1/2021 Physics 214 Fall 2011 35

Straight line motion 100 meter track event d a 11/1/2021 Physics 214 Fall 2011

Straight line motion 100 meter track event d a 11/1/2021 Physics 214 Fall 2011 36

Velocity and acceleration - d + x Remember v = Δd/Δt a = Δv/Δt

Velocity and acceleration - d + x Remember v = Δd/Δt a = Δv/Δt So the magnitude of a is not related to the magnitude of v and the direction of a is not related to the direction of v v = 0 a = + accelerating from rest v = 0 a = - reversing from rest (speed increasing) v = + a = + increasing velocity v = + a = - decreasing velocity v = - a = + slowing down v = - a = - speeding up in the – x direction 11/1/2021 Physics 214 Fall 2011 37

Graphs For a specific journey even with variable acceleration one can determine everything about

Graphs For a specific journey even with variable acceleration one can determine everything about the journey, that is d, v, a as a function of time from A distance versus time graph Or A velocity versus time graph (except the start point) Or An acceleration versus time plot (except the start velocity or the start point) 11/1/2021 Physics 214 Fall 2011 38

Summary Chapters 1 and 2 - d + x Units----Length, mass, time SI units

Summary Chapters 1 and 2 - d + x Units----Length, mass, time SI units m, kg, second Coordinate systems Average speed = distance/time = d/t Instantaneous speed = d/Δt Vector quantities---magnitude and direction Velocity----magnitude is speed Acceleration = change in velocity/time =Δv/Δt 11/1/2021 Physics 214 Fall 2011 39

One dimensional motion constant acceleration 1) v = v 0 + at velocity changes

One dimensional motion constant acceleration 1) v = v 0 + at velocity changes by the amount a every second 2) d = v 0 t + 1/2 at 2 d is the distance from the start point at t = 0 3) d = 1/2(v + v 0) t 1/2(v + v 0) is the average velocity Put t = 2 d/ (v + v 0) into v = v 0 + at 4) v 2 = v 02 + 2 ad There are only two independent equations Drag race v 0 = 0 v = 2 d/t 11/1/2021 Physics 214 Fall 2011 40

Questions Chapter 2 Q 8 A car traveling around a circular track moves with

Questions Chapter 2 Q 8 A car traveling around a circular track moves with constant speed. Is this car moving with constant velocity No, the direction is changing Q 9 A ball is thrown against a wall and bounces back toward the thrower with the same speed as it had before hitting the wall. Does the velocity of the ball change in this process? Explain. Yes, it changes direction 11/1/2021 Physics 214 Fall 2011 41

Q 10 A ball attached to a string is whirled in a horizontal circle

Q 10 A ball attached to a string is whirled in a horizontal circle such that it moves with constant speed. a. Does the velocity of the ball change in this process? Explain. b. Is the acceleration of the ball equal to zero? Explain. The velocity changes direction so there is acceleration Q 11 A ball tied to a string fastened at the other end to a rigid support forms a pendulum. If we pull the ball to one side and release it, the ball moves back and forth along an arc determined by the string length. A. Is the velocity constant in this process? Explain. B. Is the speed likely to be constant in this process? What happens to the speed when the ball reverses direction? A Both magnitude and direction change. B The speed is zero 11/1/2021 Physics 214 Fall 2011 42

Q 15 A car just starting up from a stop sign has zero velocity

Q 15 A car just starting up from a stop sign has zero velocity at the instant that it starts. Must the acceleration of the car also be zero at this instant? Explain. The acceleration is not zero, if it was the car would not move Q 17 A racing sports car traveling with a constant velocity of 100 MPH due west startles a turtle by the side of the road who begins to move out of the way. Which of these two objects is likely to have the larger acceleration at that instant? Explain. The car has zero acceleration but the turtle has acceleration 11/1/2021 Physics 214 Fall 2011 43

Q 18 In the graph shown here, velocity is plotted as a function of

Q 18 In the graph shown here, velocity is plotted as a function of time for an object traveling in a straight line. A. Is the velocity constant for any time interval shown? Explain. B. During which time interval shown does the object have the greatest acceleration? Explain. v 2 4 6 8 t (secs) A Yes from 0 – 2 seconds B From 2 – 4 seconds 11/1/2021 Physics 214 Fall 2011 44

Q 19 A car moves along a straight line so that its position (distance

Q 19 A car moves along a straight line so that its position (distance from some starting point) varies with time as described by the graph shown here. 1. Does the car ever go backward? Explain. 2. Is the instantaneous velocity at point A greater or less than that at point B? Explain. 1 Yes in the last part 2 Greater at A d B A t Q 20 For the car whose distance is plotted against time in Q 19, is the velocity constant during any time interval shown in the graph? YES 11/1/2021 Physics 214 Fall 2011 45

Q 28 A car traveling in the forward direction experiences a negative uniform acceleration

Q 28 A car traveling in the forward direction experiences a negative uniform acceleration for 10 seconds. Is the distance covered during the first 5 seconds equal to, greater than, or less than the distance covered during the second 5 seconds? Explain. If the car is always moving in the forward direction then it’s speed is higher in the first 5 seconds so the distance covered is greater 11/1/2021 Physics 214 Fall 2011 46

Ch 2 #8 - d + x Car travels with a speed of 25

Ch 2 #8 - d + x Car travels with a speed of 25 m/s What is the speed in km/s, km/h? a) 1000 m = 1 km = 0. 025 km/s 25/1000 km/sec or 25 x 10 -3 km/sec b) 3600 s = 1 hour 1 m = (1/1000)km 25 x 10 -3 x 3600 km/hr = 90 km/h 11/1/2021 Physics 214 Fall 2011 47

Ch 2 #12 - d + x v 0 = 30 m/s v =

Ch 2 #12 - d + x v 0 = 30 m/s v = 18 m/s t = 4 sec What is the average acceleration? a = (18 – 30)/4 11/1/2021 = -3 m/s/s = -3 m/s 2 Physics 214 Fall 2011 48

Ch 2 #14 - d v 0 = 5 m/s a = 1. 2

Ch 2 #14 - d v 0 = 5 m/s a = 1. 2 m/s 2 What is the final velocity? What distance is covered? + x t = 2 sec a) v = v 0 +at = 7. 4 m/s b) 11/1/2021 d = v 0 t + ½ at 2 = 12. 4 m Physics 214 Fall 2011 49

Ch 2 #16 - d v 0 = 9. 0 m/s a = -1.

Ch 2 #16 - d v 0 = 9. 0 m/s a = -1. 5 m/s 2 What is the final velocity? What distance is traveled? + x t = 2 sec a) v = v 0 + at = 6 m/s b) d = v 0 t + ½ at 2 = 15 m 11/1/2021 Physics 214 Fall 2011 50

Ch 2 CP 4 - d + x v 0 = 14 m/s a

Ch 2 CP 4 - d + x v 0 = 14 m/s a = 2 m/s 2 v = 24 m/s What is the time? What is the distance? Computed at 1 second intervals. ? a) v = v 0 + at t = 5 s b) d = v 0 t + ½ at 2 c) 1 sec = 15 11/1/2021 = 95 m 2 sec = 32 3 sec = 51 m Physics 214 Fall 2011 4 sec = 72 51

Tsunami To put the recent Tsumami in perspective we can look at the evolution

Tsunami To put the recent Tsumami in perspective we can look at the evolution of the earth for the last 250 million years 11/1/2021 Physics 214 Fall 2011 52

Current plate movements Notice the position of the Indian Subcontinent today. It moved hundreds

Current plate movements Notice the position of the Indian Subcontinent today. It moved hundreds of miles in 135 million years at a great speed (4 inches per year!!!) The Indian plate crashed into the Eurasian plate with such speed and force that it created the tallest mountain range on Earth, the Himalayas http: //www. scotese. com/futanima. htm 11/1/2021 Physics 214 Fall 2011 53

Origin and Destruction A massive change in the sea floor maybe over hundreds or

Origin and Destruction A massive change in the sea floor maybe over hundreds or a thousand miles displaces a very large volume of water and generates strong disturbances as the water tries to reach equilibrium As the tsunami crosses the deep ocean, its length from crest to crest may be a hundred miles or more, and its height from crest to trough will only be a few feet or less. They can not be felt aboard ships nor can they be seen from the air in the open ocean. In the deepest oceans, the waves will reach speeds exceeding 600 miles per hour (970 km/hr). When the tsunami enters the shoaling water of coastlines in its path, the velocity of its waves diminishes and the wave height increases. It is in these shallow waters that a large tsunami can crest to heights exceeding 100 feet (30 m) and strike with devastating force. tsunami. mov 11/1/2021 Physics 214 Fall 2011 54

Mega Tsunami’s Around the world there accumulations of material from the ocean floor called

Mega Tsunami’s Around the world there accumulations of material from the ocean floor called chevrons that could have been deposited by giant waves after a meteorite impact. Some of these have been linked to impact craters on the ocean floor. Such waves would have been 1000 feet high!! 11/1/2021 Physics 214 Fall 2011 55