Tuesday, February 23, 2010

This is what I learned about energy.  I learned that energy is a conserved substance-like quality with the capability to produce change.  I also learned that energy cannot be destroyed, it can only be transferred from object to object.  Energy can be displayed using an energy flow diagrams and bar graphs.  I have also learned that work is a measure of the amount of change that a force produces when it acts on a body.  The equation for force is W=Fx or if there is an angle, W-Fx cos theta.  The unit of work is a joule.  Power is the rate at which work is done by a force.  The equation for power equals P=Fv.  There are four types of energy.  The first type is kinetic energy which is the energy a body has by virtue of its motion.  The equation is KE=1/2mv^2.  The second type of energy is Potential energy, which is the gravitational potential energy of a body.  The equation for it is PE=mgh.  The third type of energy is elastic potential energy, which is associated with elastic materials.  The equation is PEe=1/2kx^2.  The last type of energy is mechanical energy, which is the sum of kinetic energy and all forms of potential energy.  Its equation is ME=PE+KE.

What I have found difficult about what I have studied is the energy flow diagrams.  At first I did not understand how they are qualitative, not quantitative, but now, I understand the energy flow diagrams.  Another confusing thing about this subject is the concepts of energy.  I really did not understand how energy could be transferred at first, but now all of the concepts come easily to me.

My problem-solving skills are fine for this subject.  At first, I did not understand how to solve the equations with power, but then realized Fg was the force they were looking for.  Also, the problems with elastic energy were difficult at first.  I now realize how to do the problems

Can you make any connection(s) between what we studied and everyday life, history, situations in the world, any other subject you are studying or your own experiences? 

Yes. If you move, hit, or push anything, there is a transfer of energy happening.  When playing basketball, when the ball hits the floor, the floor will hit the ball back up to you.  Also, in football, when a head on collision happens, the player who delivers the most power will knock the other one down on the field 

Monday, February 1, 2010

My project is about Newton's Third Law and the action-reaction pairs that apply to baseball.  I have a glog that will go into depth about my idea and i have a video from GoAnimate which is for your viewing pleasure. 

GoAnimate.com: Physics of Baseball by jonnyboy721

Like it? Create your own at GoAnimate.com. It's free and fun!