2/27/12 - 6th Grade Review

Guys,

Today we read about Newton's 2nd and 3rd Laws of Motion.  A lot of the information has been covered already  but to highlight some of the important things from today.

Newton's 2nd Law - Force = Mass x Acceleration or as we have been saying Force is for your MAMA. This is a great way to see the relationship that exists between force, mass, and acceleration.


Gravity - The force that exists between two objects.  It depends purely on the MASS of the two objects and the DISTANCE APART those two objects are.  The image below gives you a good idea of what this  means.

Image courtesy of http://mail.colonial.net

Mass - The amount of "stuff" an object has.

Weight - The force of gravity acting on the mass of an object.

Newton's 3rd Law - For every action there is an EQUAL and OPPOSITE reaction.  

Equal and Opposite

Photo courtesy of www.wikipedia.org

We learned that although these forces are equal and opposite, they do not always cancel each other out.  Mass of the two objects plays a big part of which objects feels more of the force.  Take the example of hammering a nail into a wall.  The forces are equal and opposite but the nail goes into the wall an there is very little kick back from the force of the nail on the hammer.  This is because the mass of the hammer is much greater than that of the nail.

Photo courtesy of www.ipodphysics.com

I handed out a review sheet that I have posted on the homework site for those of you who might have been absent.  Nothing is officially due tomorrow but I would advise you to try and get most of the worksheet done so I can answer any questions you might have on anything.  Your test is on Wednesday so tomorrow will be the last chance to clear up anything that is still confusing.