If you missed today in 2013-2014 we:
1.  Handed out the Feb. calendar.  To make up the two snow days last week we are not doing the single elimination power roll off and the bullet proof vest day will try to be done on over other days this week.
2.  We alternated grading a few problems on the homework sheet with doing demonstrations.

If you missed today:  The below is from 2012-2013 school year.

We pointed out that after doing work against gravity (lifting an object) that the amount of work done in the vertical direction ( Work = Force X Displacement ) (the force and displacement have to be in the same direction, vertically up in this case) is equal to the increase in Potential Energy (it is the very same magnitude (meaning #) in Joules) but if the object is let go, the kinetic energy increases at the same rate the potential energy decreases so that the sum of the two (P.E. total at the top = P.E. lost as it falls + K.E. gained as it falls = K.E. total at the very bottom of the fall just before hitting bottom).  The Mechanical Equivalent of Heat showed that the K.E. total at the bottom of the fall because the quantity of heat gained by the contacting materials after the object hits.

A demonstration to point out the conservation of energy is using a pendulum by having a massive object swung up to the height of your face and let go.  If you trust the conservation of energy, you know that the object cannot swing back higher than you let it go so it cannot hit you.  But as you see that massive object coming at your face you tend to have doubts and back up.  It is important to just let the object go and not push it away from you, it is also important not to lean forward with you face after letting go.  Safety precautions are taken by someone letting you know if you leaned forward, or putting your fist between your face and the object just brought up to your face.  Videos taken each period below starting with Mr. Flasch the school night before after he set the demonstration up for us.

We also worked on homework..

Period 1            Period 4            Period 5            Period 7            Period 8 Pd. 8 Previous a    Pd. 8 Previous b

Videos of students having a swinging time like Mr. Flasch above left...trusting the Physics.  The weight cannot return higher than it was dropped from unless pushed or the student leaned forward after letting it go.