Frames of reference

Have you ever been resting in your friends parked car in a parking lot, not really paying attention, waiting for friends to come back with your coffee and you notice the car beside you move.  Your initial reaction is that you are moving.  That is a perfect example of frames of reference.  

The motion you see is based on how you look at it at or where you view the motion from.  I really can't explain it any better then how these two Professors did it back in 1960. I first saw this in high school and is excellent.

It is presented by Prof. Ivey and Prof. Hume of the University of Toronto.  

Well worth the 30 minutes it takes to watch!

Click here and enjoy!

Inertia

Inertia, more commonly known as Newton's first law.

I'll start with this picture and explain about it farther down.

Have you ever been sitting on a couch, watching your favorite show and the phone rings but the phone is in the other room and you don't feel like getting up to get it...well... that is inertia.

A very simple summary of the rule is "What ever the object tends to be doing at any given time, it wants to keep doing that."

The heavier, more massive, the object, the more inertia it has.  

Picture a piano...try to move it..pretty tough..now picture a piano moving.. it'll be pretty hard to stop.  That is an example of Inertia.

Another way of looking at it is this..

Picture yourself pushing car.. now try to push it as hard and as fast as you can.  If you push the car hard and fast enough you can actually put a dent in the trunk as you push it because the car didn't move as you were pushing it because of it's large inertia/mass...

Now picture the same thing but in a larger setting.. and thanks to Mythbusters you can actually see it.

The theme of this show..and overall a great critical thinking show at that.. was to try to have two trucks hit a car on opposites sides at the same time and crush it.  The problem was they couldn't time it right.  The trucks never hit the car at the same time.  So thanks to their success they have an almost unlimited budget and they were able to do something awfully cool. They were able to

 do this experiment with a rocket sled.  They put a car up against a brick wall and then tried to slam a rocket sled into the car to squish the car at both ends... seems logical... you push a car at one side the car gets pushed into the wall, so  both ends gets squished at the same time... well they forgot to remember Newton's First law..INERTIA.  The car is being pushed so quickly that the cars inertia is easily visible and the car refuses to move.

Here are three picturess from the above video.. you have to watch the video to truly see the effect...

Notice how the back wheel hardly moved while it was being "squished".  The cars inertia allowed it to be crushed on one side and not dented at all on the other.

Now that is cool...

In future posts I'll get more into inertia but what a great introduction to Inertia...

 and you have to admit..

Ugottaluvphysics.

Physics..the language..

Language..language.. language...

Everything has language..and language is sometimes confusing... but we need it...

A good example is in sports. Three of my favourite sports come to mind which have the same rule and each rule has a different meaning...

Rugby, hockey and soccer all have the offside rule...all have different meanings.  They needed a name to call the rule so they decided, for one reason or another to call it offside.  It could have been named other things but I'm happy to accept they used offside..confusing yes but acceptable..  To clarify my point, if you know nothing about either of the games but you know someone who does, try to get them to explain what offside means. Confusing huh!! Now try to get them to write a nice clear concise definition of it on paper... probably sounds gibberish if you don't understand the language of the game...But once you get to know the language of the sport it actually makes sense... 

Imagine reading the rules of rugby and they mention hooker, tight five, standoff, loose head, tight head, ruck, maul, up and under etc... your head would be spinning with the jargon..but once you get with the game it actually makes perfect sense... and is then more fun to both watch, play and coach...

The number of nights killed arguing the rules and decisions players made while playing any game (and having a few beverages at the same time) is great entertainment.  It makes the game more fun to watch and play.. and as a viewer you appreciate the nuances more.

Same can be said with physics (or any other science or just about any other job/skill/occupation for that matter).  It really isn't that bad once you get to know the language.  But you must be willing to learn the language.  It comes easier to some as too others but that is normal.  It is just like other things in life.  My golf game is awful but my billiard playing is a heck of a lot better, (mainly because I put a lot more time into it..My swing could just be as good if I put the time into it)  but i enjoy both just as much.

In physics you have a whole bunch of terms Inertia, Force, charge, poles, mass, momentum etc.  They sound confusing but they really aren't that bad once you get to know what they mean.  It may sound weird to some but talking about physics makes me appreciate physics that much more.  Just like talking about a good hockey game.  I have numerous friends (in and outside of teaching) who love talking physics.  The nice thing about physics is I don't need to go anywhere to see physics in action like, for example, if i want to go see a live rugby game.  For rugby I have to go to the rugby pitch to see a game Saturday afternoon.  With physics I can walk out my door anytime and see physics in action.

In the upcoming posts I'll try to take some of the mystery out of the terms.  If you also find someone or some forum or other blog that discusses physics you will learn to appreciate it that much more.  Keep an open mind....  I'm always learning about physics.  Just like about my favourite sports.  And I hope you get to learn to like the language of physics.  It will make it easier to then read about it and maybe even speak about it more often...  since you know..

Ugottaluvphysics!

Everyone knows Physics!!

Its true!!! You do know physics!!

Even though you might  cringe at the sound of the word physics... probably because of that "horrible" physics course you took in high school or the fact you avoided it because the course involved math.. you actually have a very good understanding of physics.

Physics is used every time you:

1) walk since you are constantly shifting your center of mass since you know that if you don't do so you will fall...

2) stop your car..you figure out how hard you need to use the brakes to just stop in time..well most of us can :) ... (oh that reminds me...don't talk on the cell phone while driving the car...)

3) play sports... the physics behind hitting a golf ball, throwing a baseball, heading/trapping a soccer ball, etc..requires you to analyse the motion to determine what all your muscles of your joints need to do get the desired affects.. (I myself still can't figure out the "physics" behind golf..my slice contests to that, but I can at least "hit" the ball.. :) )

To name a few..

You certainly appreciate what Physics can do in everyday life....

Physics is in action when you:

use the cell phone, look at a rainbow, see a "falling star", watch TV, use your mp3 player, play a video game, go on a trip, ride a bike, rent a movie, go to a movie, see a satellite move in the night sky (they are easy to find..you should try it some time..just after sunset look up...you will soon see a "moving star"..it is most likely a satellite.), watch a rocket launch, bounce a ball, turn on a light switch, cook dinner, drink your favourite beverage, read a book, see Christmas lights, go to a concert, watch fire works etc..

Physics was used to make it happen in one way or another...

So regardless whether you like physics or dread hearing its word, it is there, you can't avoid it....

The purpose of the blog is to help make you not dread it so much and maybe have you appreciate physics some more.  And yes maybe give it some LUV!!

And remember...physics isn't math...but if you like math you can actually do some pretty cool physics...  

I'll try to help you do a little bit of both...appreciate and do.... some physics.  So don't be shy..

because you know... Ugottaluvphysics!