Physics is Fun and so is Friction

Friction is fun, yes it is.  Friction first of is noted as "f", a little f so as not to be confused with the big "F" of force.  f=(mu)(normal force); mu is pronounced as "mew" as appears as a lower case "u" with a longer first stroke, thus f=un (the u is the mu-best attempt).  Friction as defined as "a force that resists the motion of one object sliding past another."  Friction enables us to walk, run, and sit.  If there was no friction we would slip and slide and not be able to stand up.  Friction can be broken up into static friction, a "force that resists the sliding motion of two objects that are stationary relative to one another" and kinetic friction "when an object slides along another".  Static friction requires more force to overcome it and make the object move.  Kinetic friction requires less because the object is currently in motion and has moving inertia.  This explains why it is harder to get things moving at first then it is to continue to move said object.  In the background, I am moving the block of wood up the wall.  As stated in the definition of friction, in this example, friction would be working against my force in a downwards direction.  Conversely if I were to hold the block in place the block would want to move down and friction would then be upwards.  Not the best example of friction, I'm sure, but this just goes to show that Physics is always all around us and sometimes goes unnoticed.

Newton's 3rd Law and its Numerous Applications

Sitting around wondering what to do for my journal I realized that any picture I could possibly take applied to Newton's second law.  BTW: the reason for the exact same picture setting is not only for my convenience but also to show how physics can relate anywhere even right at home.  Moving right along, Newton's second law is defined by Kinetic Books as "A change in motion is proportional to the motive force impressed and takes place along the straight line in which that force is impressed."  As seen in my picture that blogger was not letting me upload, but hopefully by the time I post this it should be up there.  Anyways, the clear box I'm holding up has a net force acting upon it, or the sum of the force impressed by me carrying it and its weight of the box opposing my force.  The force of holding up the box would be signified as an upward arrow labeled with a "F" pointing up from the box.  The weight or mg would be pointing just the opposite.  The equation net force equals mass (of the object acted upon) and the acceleration or acceleration equals net force divided by the mass can help find anything having to do with Newton's second law.  In fact, this equation is the epitome of the second law expressing all the factors engaged in any action thinkable.  (well mostly)  In the picture this extends to all the objects, even me.  On anything that  is moved there is always at least two always acting upon it; the force applied to it i.e. push, pull and the weight of the object exerting its own force, both of these added together is the net force.  If the force applied is greater then the mg "all other things held constant" (ceteris paribus) the object will move.  If it is less the object will stay where it was.  So a net force is being applied in my picture to the box, to me, the chair, the shelf, the trophies, the book, and all other items you can name.  Hah well that's it for this journal, have fun with your journals and look out for Newton's laws in action!