11-6-08

WOOOHOOO!!! Today is November 6, 2008! In the absoultely, crazy, awsome world of fifth period physics with everyones favorite teacher, the Mr. "the Man" Manning, we began discussing Newton's awsome 2nd Law of acceleration!!! But first.....The DAILY QUESTION! Part 1: Why does Newton's 2nd Law state that a NET force causes an acceleration? Why not just one force? Answer: There could be more than one force acting on the object! Part 2: If the acceleration triples for a constant amount of the net force, how did the mass of the object change? Answer: The objects mass decreases by 1/3. Example: Net Force=ma 15N=m*3 m/s/s 15N=m*9 m/s/s 5kg=m 1.67kg=m The example above proves that if an acceleration triples, the mass of the object decreases by 1/3. Now, for Newton's 2nd Law!!!! 2nd Law states:"The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." Algebraically this is expressed as: ΣF=ma When "ΣF" is positive "a" is also positive likewise, when "ΣF" is negative, "a" is negative. You may be sitting at your computer reading this finely crafted TPJ, thinking.......WHY THE @#$% IS THAT!!!! If so, your are in luck, because I am going nice enough to let you in on the secrect behind this phenomena. The reason behind this is that there is an equal sign between the two variables!!!!!!!!!!!!!!! When multiplying mass (almost always positive) by the acceleration(+ or-) the sign of your answer will be your net force. Now al of your who did not know this will be able to sleep soundly at night! Today's handouts include "Newton's 2nd Law Applications: pages 7-11.