Publisher: O'Reilly Media Released: September 2008 Pages: 942
Wouldn't it be great if there were a physics book that showed you how things work instead of telling you how? Finally, with Head First Physics, there is. This comprehensive book takes the stress out of learning mechanics and practical physics by providing a fun and engaging experience, especially for students who "just don't get it."
Head First Physics offers a format that's rich in visuals and full of activities, including pictures, illustrations, puzzles, stories, and quizzes  a mixedmedia style proven to stimulate learning and retention. One look will convince you: This isn't mere theory, this is physics brought to life through realworld scenarios, simple experiments, and hypothetical projects. Head First Physics is perfect for anyone who's intrigued by how things work in the natural world.
You'll quickly discover that physics isn't a dry subject. It's all about the world we live in, encompassing everything from falling objects and speeding cars, to conservation of energy and gravity and weightlessness, and orbital behavior. This book:
 Helps you think like a physicist so you can understand why things really work the way they do
 Gives you relevant examples so you can fully grasp the principles before moving on to more complex concepts
 Designed to be used as a supplement study guide for the College Board's Advanced Placement Physics B Exam
 Introduces principles for the purpose of solving realworld problems, not memorization
 Teaches you how to measure, observe, calculate  and yes  how to do the math
 Covers scientific notation, SI units, vectors, motion, momentum conservation, Newton's Laws, energy conservation, weight and mass, gravitation and orbits, circular motion and simple harmonic motion, and much more
If "Myth Busters" and other TV programs make you curious about our physical world  or if you're a student forced to take a physics course  now you can pursue the subject without the dread of boredom or the fear that it will be over your head. Head First Physics comes to rescue with an innovative, engaging, and inspirational way to learn physics!


Chapter 1 Think Like a Physicist: In the beginning ... 
Physics is the world around you 
You can get a feel for what’s happening by being a part of it 
Use your intuition to look for ‘special points’ 
The center of the earth is a special point 
Ask yourself “What am I ALREADY doing as I reach the special point?” 
Where you’re at  and what happens next? 
Now put it all together 
Your Physics Toolbox 
Chapter 2 Making it all MEAN Something: Units and measurements 
It’s the best music player ever, and you’re part of the team! 
So you get on with measuring the myPod case 
When the myPod case comes back from the factory... 
...it’s waaay too big! 
There aren’t any UNITS on the blueprint 
You’ll use SI units in this book (and in your class) 
You use conversion factors to change units 
You can write a conversion factor as a fraction 
Now you can use the conversion factor to update the blueprint 
You just converted the units for the entire blueprint! 
But there’s STILL a problem ... 
What to do with numbers that have waaaay too many digits to be usable 
How many digits of your measurements look significant? 
Generally, you should round your answers to three significant digits 
Is it OK to round the myPod blueprint to three significant digits? 
You ALREADY intuitively rounded your original myPod measurements! 
Any measurement you make has an error (or uncertainty) associated with it 
The error on your original measurements should propagate through to your converted blueprint 
Right! Time to attack the blueprint again! 
STOP!! Before you hit send, do your answers SUCK?! 
You nailed it! 
When you write down a measurement, you need the right number of significant digits 
Your Physics Toolbox 
Chapter 3 Scientific Notation, Area, and Volume: All numbers great and small 
A messy college dorm room 
So how long before things go really bad? 
Power notation helps you multiply by the same number over and over 
Your calculator displays big numbers using scientific notation 
Scientific notation uses powers of 10 to write down long numbers 
Scientific notation helps you with small numbers as well 
You’ll often need to work with area or volume 
Look up facts in a book (or table of information) 
Prefixes help with numbers outside your comfort zone 
Scientific notation helps you to do calculations with large and small numbers 
The guys have it all worked out 
200,000,000 meters cubed bugs after only 16 hours is totally the wrong size of answer! 
Be careful converting units of area or volume 
So the bugs won’t take over ... unless the guys sleep in! 
Question Clinic: The “Converting units of area or volume” Question 
Your Physics Toolbox 
Chapter 4 Equations and Graphs: Learning the lingo 
The new version of the Break Neck Pizza website is nearly ready to go live ... 
...but you need to work out how to give the customer their delivery time 
If you write the delivery time as an equation, you can see what’s going on 
Use variables to keep your equation general 
You need to work out Alex’s cycling time 
When you design an experiment, think about what might go wrong! 
OK  time to recap where you’re at... 
Conduct an experiment to find out Alex’s speed 
Write down your results... in a table 
Use the table of distances and times to work out Alex’s speed 
Random errors mean that results will be spread out 
A graph is the best way of taking an average of ALL your results 
Use a graph to show Alex’s time for ANY distance 
The line on the graph is your best estimate for how long Alex takes to cycle ANY distance 
You can see Alex’s speed from the steepness of the distancetime graph 
Alex’s speed is the slope of the distancetime graph 
Now work out Alex’s average speed from your graph 
You need an equation for Alex’s time to give to the web guys 
Rearrange the equation to say “Δ time = something” 
Use your equation to work out the time it takes Alex to reach each house 
So you do a test run with the website ... 
So just convert the units, and you’re all set...right? 
Include the cooking time in your equation 
The Break Neck website goes live, and the customers love it! 
A few weeks later, you hear from Break Neck again 
A graph lets you see the difference the stop lights made 
The stop lights change Alex’s average speed 
Add on two minutes per stop light to give the customer a maximum delivery time ... 
...the customers are extremely happy ... 
...and you’re invited to the Pizza Party 
Question Clinic: The “Did you do what they asked you” Question 
Your Physics Toolbox 
Chapter 5 Dealing with Directions: Vectors 
The treasure hunt 
Displacement is different from distance 
Distance is a scalar; displacement is a vector 
You can represent vectors using arrows 
You found the next clue... 
You can add vectors in any order 
Well done  you’ve found the third clue! 
Question Clinic: The “Wheat from the chaff” Question 
Angles measure rotations 
Now you can get on with clue 3! 
If you can’t deal with something big, break it down into smaller parts 
You move onto the fourth clue... 
Velocity is the ‘vector version’ of speed 
Write units using shorthand 
So, on to clue 4 ... 
You need to allow for the stream’s velocity too! 
If you can find the stream’s velocity, you can figure out the velocity for the boat 
It takes the boat time to accelerate from a standing start 
How do you deal with acceleration? 
So it’s back to the boat ... 
Vector, Angle, Velocity, Acceleration = WINNER!!! 
Your Physics Toolbox 
Question Clinic: The “Design an experiment” Question 
Chapter 6 Displacement, Velocity, and Acceleration: What’s going on? 
Just another day in the desert ... 
...and another DingoEmu moment! 
How can you use what you know? 
The cage accelerates as it falls 
‘ Vectorize’ your equation 
You want an instantaneous velocity, not an average velocity 
You already know how to calculate the slope of a straight line... 
A point on a curved line has the same slope as its tangent 
The slope of something’s velocitytime graph lets you work out its acceleration 
Work out the units of acceleration 
Success! You worked out the velocity after 2.0 s  and the cage won’t break! 
Now onto solve for the displacement! 
Your Physics Toolbox 
Chapter 7 Equations of motion (part 1): Playing With Equations 
How high should the crane be? 
Graphs and equations both represent the real world 
You’re interested in the start and end points 
You have an equation for the velocity  but what about the displacement? 
See the average velocity on your velocitytime graph 
Test your equations by imagining them with different numbers 
Calculate the cage’s displacement! 
You know how high the crane should be! 
But now the Dingo needs something more general 
A substitution will help 
Get rid of the variables you don’t want by making substitutions 
Continue making substitutions ... 
You did it  you derived a useful equation for the cage’s displacement! 
Check your equation using Units 
Check your equation by trying out some extreme values 
Your equation checks out! 
Question Clinic: The “Substitution” Question 
Question Clinic: The “Units” or “Dimensional analysis” Question 
Think like a physicist! 
Your Physics Toolbox 
Chapter 8 Equations of Motion (Part 2): Up, up, and... back down 
Previously ... 
Now ACME has an amazing new cage launcher 
The acceleration due to gravity is constant 
Velocity and acceleration are in opposite directions, so they have opposite signs 
You can use one graph to work out the shapes of the others 
Is a graph of your equation the same shape as the graph you sketched? 
Ready to launch the cage! 
Fortunately, ACME has a rocketpowered hovercraft! 
You can work out a new equation by making a substitution for t 
Multiply out the parentheses in your equation 
You have two sets of parentheses multiplied together 
Where you’re at with your new equation 
You need to simplify your equation by grouping the terms 
You can use your new equation to work out the stopping distance 
There are THREE key equations you can use when there’s constant acceleration 
You need to work out the launch velocity that gets the Dingo out of the Grand Canyon! 
The launch velocity’s right! 
You need to find another way of doing this problem 
Question Clinic: The “Sketch a graph” or “Match a graph” Question 
Question Clinic: The “Symmetry” and “Special points” Questions 
Your Physics Toolbox 
Chapter 9 Triangles, Trig and Trajectories: Going twodimensional 
Camelot  we have a problem! 
How wide should you make the moat? 
Looks like a triangle, yeah? 
A scale drawing can solve problems 
Pythagoras’ Theorem lets you figure out the sides quickly 
Sketch + shape + equation = Problem solved! 
You kept them out! 
But the attackers get smarter! 
Camelot ... we have ANOTHER problem! 
Relate your angle to an angle inside the triangle 
Classify similar triangles by the ratios of their side lengths 
Sine, cosine and tangent connect the sides and angles of a rightangled triangle 
How to remember which ratio is which?? 
Calculators have sin(θ), cos(θ) and tan(θ) tables built in 
Back at the castle, everyone’s depending on you! 
You can know everything! * 
Does your answer SUCK? 
Uh oh. Gravity... 
The cannonball’s velocity and acceleration vectors point in different directions 
Gravity accelerates everything downwards at 9.8 m/s2 
The horizontal component of the velocity can’t change once you’ve let go 
The horizontal component of a projectile’s velocity is constant 
The same method solves both problems 
Question Clinic: The “Projectile” Question 
And so they ran away ... 
Question Clinic: The “Missing steps” Question 
Your Physics Toolbox 
Chapter 10 Momentum Conservation: What Newton Did 
The pirates be havin’ a spot o’ bother with a ghost ship ... 
What does the maximum range depend on? 
Firing at 45° maximizes your range 
You can’t do everything that’s theoretically possible  you need to be practical too 
SiegesRUs has a new stone cannonball, which they claim will increase the range! 
Massive things are more difficult to start off 
Massive things are more difficult to stop 
Newton’s First Law 
Mass matters 
A stone cannonball has a smaller mass  so it has a larger velocity. But how much larger? 
Here’s your lab equipment 
How are force, mass and velocity related? 
Vary only one thing at a time in your experiment 
Mass x velocity  momentum  is conserved 
A greater force acting over the same amount of time gives a greater change in momentum 
Write momentum conservation as an equation 
Momentum conservation and Newton’s Third Law are equivalent 
You’ve calculated the stone cannonball’s velocity... 
...but you want the new range! 
Use proportion to work out the new range 
You solved the pirates’ problem! 
Question Clinic: The “Proportion” Question (often multiple choice) 
Your Physics Toolbox 
Chapter 11 Weight and the normal force: Forces for courses 
WeightBotchers are at it again! 
Is it really possible to lose weight instantly?! 
Scales work by compressing or stretching a spring 
Mass is a measurement of “stuff” 
Weight is a force 
The relationship between force and mass involves momentum 
If the object’s mass is constant, Fnet = ma 
The scales measure the support force 
Now you can debunk the machine! 
The machine reduces the support force 
Force pairs help you check your work 
You debunked WeightBotchers! 
But WeightBotchers are back! 
A surface can only exert a force perpendicular (or normal) to it 
When you slide downhill, there’s zero perpendicular acceleration 
Use parallel and perpendicular force components to deal with a slope 
Another fake busted! 
Question Clinic: The “Free body diagram” Question 
Question Clinic: The “Free body diagram” Question 
Your Physics Toolbox 
Chapter 12 Using forces, momentum, friction and impulse: Getting on with it 
It’s ... SimFootball! 
Momentum is conserved in a collision 
But the collision might be at an angle 
A triangle with no right angles is awkward 
Use component vectors to create some rightangled triangles 
The programmer includes 2D momentum conservation ... 
...but the players keep on sliding for ever! 
In real life, the force of friction is present 
Friction depends on the types of surfaces that are interacting 
Friction depends on the normal force 
Be careful when you calculate the normal force 
You’re ready to use friction in the game! 
Including friction stops the players from sliding forever! 
The sliding players are fine  but the tire drag is causing problems 
Using components for the tire drag works! 
Question Clinic: The “Friction” Question 
How does kicking a football work? 
FΔt is called impulse 
The game’s great  but there’s just been a spec change! 
The strength of the moon’s gravitational field is lower then the Earth’s 
For added realism, sometimes the players should slip 
You can change only direction horizontally on a flat surface because of friction 
The game is brilliant, and going to XForce rocks! 
Newton’s Laws give you awesome powers 
Your Physics Toolbox 
Chapter 13 Torque and Work: Getting a lift 
Half the kingdom to anyone who can lift the sword in the stone ... 
Can physics help you to lift a heavy object? 
Use a lever to turn a small force into a larger force 
Do an experiment to determine where to position the fulcrum 
Zero net torque causes the lever to balance 
Use torque to lift the sword and the stone! 
Question Clinic: The “Two equations, two unknowns” Question 
So you lift the sword and stone with the lever ... 
...but they don’t go high enough! 
You can’t get something for nothing 
When you move an object against a force, you’re doing work 
The work you need to do a job = force x displacement 
Which method involves the least amount of work? 
Work has units of Joules 
Energy is the capacity that something has to do work 
Lifting stones is like transferring energy from one store to another 
Energy conservation helps you to solve problems with differences in height 
One of our stackable stones is missing ... 
Will energy conservation save the day? 
You need to do work against friction as well as against gravity 
Doing work against friction increases internal energy 
Heating increases internal energy 
It’s impossible to be 100% efficient 
Your Physics Toolbox 
Chapter 14 Energy Conservation: Making your life easier 
The ultimate bobsled experience 
Forces and component vectors solve the first part ... 
...but the second part doesn’t have a uniform slope 
A moving object has kinetic energy 
The kinetic energy is related to the velocity 
Calculate the velocity using energy conservation and the change in height 
You’ve used energy conservation to solve the second part 
In the third part, you have to apply a force to stop a moving object 
Putting on the brake does work on the track 
Doing work against friction increases the internal energy 
Energy conservation helps you to do complicated problems in a simpler way 
There’s a practical difference between momentum and kinetic energy 
Question Clinic: The “Show that” Question 
Question Clinic: The “Energy transfer” Question 
After the roaring success of SimFootball, it’s time for SimPool 
Momentum conservation will solve an inelastic collision problem 
You need a second equation for an elastic collision 
Energy conservation gives you the second equation that you need! 
Factoring involves putting in parentheses 
You can deal with elastic collisions now 
In an elastic collision, the relative velocity reverses 
The pool ball collisions work! 
There’s a gravitydefying trick shot to sort out ... 
Where is the problem with the programmer’s reasoning? 
The initial collision is inelastic  so mechanical energy isn’t conserved 
Use momentum conservation for the inelastic part 
Question Clinic: The “Ballistic pendulum” Question 
Your Physics Toolbox 
Chapter 15 Tension, Pulleys and Problem Solving: Changing direction 
It’s a bird... it’s plane... 
...no, it’s... a guy on a skateboard?! 
Always look for something familiar 
Michael and the stack accelerate at the same rate 
Use tension to tackle the problem 
Look at the big picture as well as the parts 
But the day before the competition ... 
Using energy conservation is simpler than using forces 
There goes that skateboard... 
Your Physics Toolbox 
Chapter 16 Circular Motion (Part 1): From α to ω 
Limber up for the Kentucky Hamster Derby 
You can revolutionize the hamsters’ training 
Thinking through different approaches helps 
A circle’s radius and circumference are linked by Π 
Convert from linear distance to revolutions 
Convert the linear speeds into Hertz 
So you set up the machine ... 
...but the wheel turns too slowly! 
Try some numbers to work out how things relate to each other 
The units on the motor are radians per second 
Convert frequency to angular frequency 
The hamster trainer is complete! 
A couple of weeks later ... 
You can increase the (linear) speed by increasing the wheel’s radius 
Question Clinic: The “Angular quantities” Question 
Your Physics Toolbox 
Chapter 17 Circular Motion (Part 2) Staying on track 
Houston ... we have a problem 
When you’re in freefall, objects appear to float beside you 
What’s the astronaut missing, compared to when he’s on Earth? 
Can you mimic the contact force you feel on Earth? 
Accelerating the space station allows you to experience a contact force 
You can only go in a circle because of a centripetal force 
Centripetal force acts towards the center of the circle 
The astronaut experiences a contact force when you rotate the space station 
What affects the size of centripetal force? 
Spot the equation for the centripetal acceleration 
Give the astronauts a centripetal force 
The astronauts want as much floor space as possible 
Here, the floor space is the area of a cylinder’s curved surface 
If you work out the volume, you can calculate the astronauts’ floor space 
Let’s test the space station... 
Fewer uncomfortable things happen with the 100 m radius space station 
You’ve sorted out the space station design! 
Question Clinic: The “Centripetal force” Question 
Back to the track! 
The bobsled needs to turn a corner 
Angling the track gives the normal force a horizontal component 
When you slide downhill, there’s no perpendicular acceleration 
When you turn a corner, there’s no vertical acceleration 
How to deal with an object on a slope 
Banking the track works ... 
...but now they want it to looptheloop! 
The “support force” (normal force or tension force) required for a vertical circle varies 
Any force that acts towards the center of the circle can provide a centripetal force 
How fast does the bobsled need to go? 
Question Clinic: The “Banked curve” Question 
Question Clinic: The “Vertical circle” Question 
Your Physics Toolbox 
Chapter 18 Gravitation and Orbits: Getting away from it all 
Party planners, a big event, and lots of cheese 
What length should the cocktail sticks be? 
The cheese globe is a sphere 
The surface area of the sphere is the same as the surface area of the cheese 
Let there be cheese... 
...but there are gaps in the globe! 
The party’s on! 
To infinity  and beyond! 
Earth’s gravitational force on you becomes weaker as you go further away 
Gravitation is an inverse square law 
Now you can calculate the force on the spaceship at any distance from the Earth 
The potential energy is the area under the forcedisplacement graph 
If U = 0 at infinity, the equation works for any star or planet 
Use energy conservation to calculate the astronaut’s escape velocity 
We need to keep up with our astronaut 
The centripetal force is provided by gravity 
With the comms satellites in place, it’s Pluto (and beyond) 
Question Clinic: The “gravitational force = centripetal force” Question 
Your Physics Toolbox 
Chapter 19 Oscillations (Part 1): Round and round 
Welcome to the fair! 
Reproduce the duck on the display 
The screen for the game is TWODIMENSIONAL 
So we know what the duck does... 
...but where exactly is the duck? 
Any time you’re dealing with a component vector, try to spot a rightangled triangle 
Let’s show Jane the display 
The second player sees the xcomponent of the duck’s displacement 
We need a wider definition of cosine, too 
sine and cosine are related to each other 
Let the games begin! 
Jane’s got another request: What’s the duck’s velocity from each player’s point of view? 
Get the shape of the velocitytime graph from the slope of the displacementtime graph 
The game is complete! 
Your Physics Toolbox 
Chapter 20 Oscillations (Part 2): Springs ‘n’ swings 
Get rocking, not talking 
The plant rocker needs to work for three different masses of plant 
A spring will produce regular oscillations 
Displacement from equilibrium and strength of spring affect the force 
A mass on a spring moves like a sideon view of circular motion 
A mass on a spring moves with simple harmonic motion 
Simple harmonic motion is sinusoidal 
Work out constants by comparing a situationspecific equation with a standard equation 
Question Clinic: The “This equation is like that one” Question 
You rock! Or at least Anne’s plants do 
But Anne forgot to mention someting ... 
The plants rock  and you rule! 
But now the plant rocker’s frequency has changed ... 
The frequency of a horizontal spring depends on the mass 
Will using a vertical spring make a difference? 
A pendulum swings with simple harmonic motion 
What does the frequency of a pendulum depend on? 
The pendulum design works! 
Question Clinic: The “Vertical spring” Question 
Question Clinic: The “How does this depend on that” Question 
Your Physics Toolbox 
Chapter 21 Think Like a Physicist: It’s the final chapter 
You’ve come a long way! 
Now you can finish off the globe 
The roundtrip looks like simple harmonic motion 
But what time does the roundtrip take? 
You can treat the Earth like a sphere and a shell 
The net force from the shell is zero 
The force is proportional to the displacement, so your trip is SHM 
Question Clinic: The “Equation you’ve never seen before” Question 
You know your average speed  but what’s your top speed? 
Circular motion from side on looks like simple harmonic motion 
You can do (just about) anything! 
Appendix Leftovers: The top 6 things (that we didn’t cover before, but are covering now) 
#1 Equation of a straight line graph, y = mx + c 
#2 Displacement is the area under the velocitytime graph 
#3 Torque on a bridge 
#4 Power 
#5 Lots of practice questions 
#6 Exam tips 
Appendix Equation Table: Point of Reference 
Mechanics equation table 
 Title:
 Head First Physics
 By:
 Heather Lang
 Publisher:
 O'Reilly Media
 Formats:

 Print
 Ebook
 Safari Books Online
 Print:
 September 2008
 Ebook:
 June 2009
 Pages:
 942
 Print ISBN:
 9780596102371
  ISBN 10:
 0596102372
 Ebook ISBN:
 9780596557270
  ISBN 10:
 0596557272


Heather Lang Heather Lang has a physics degree, a PhD in the grey area between biochemistry and physics, and international caps at both chess and cricket. She has a great interest in educational and coaching methods and has run afterschool chess clubs for a number of years, bringing many complete beginners on to national and international level. Heather has been able to transfer many of these successful methods across to her book Head First Physics. She is also the coauthor of the Babar Particle Physics Teaching Package (Manchester University Department of Physics and Astronomy, 1999) and joint first author of a 2002 Nature Immunology paper with a lot of jargon and some pretty pictures in it. View Heather Lang's full profile page. 
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11/13/2009 (10 of 11 customers found this review helpful) 4.0Replies to some criticisms By Glorious Ruler Of All Spacetime from Stanford  Easy to understand
 Helpful examples
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