Physics 30 - March 31 & April 1

Yesterday in class we learned about Newton's Third Law of Motion, or the action-reaction law.  We learned about the implications of such an important law and how often we use this law and don't realize it.  I assigned Assignment 3.3 at the end of the class.

Today we started to look at specific types of forces.  We began with an examination of the force of gravity.  This is also called an object's weight, although not to be confused with an object's mass.  The one lesson I wanted students to learn today is that mass and weight do not mean the same thing.  Mass is a measure of the amount of matter an object has whereas weight is the force of gravity on that object.  One is measured in kilograms, the other in newtons. 

We learned about the differences between weight and the normal force and also learned what exactly a bathroom scale is measuring.  The concept of apparent weight is really important for students to understand.  This was all covered on slides 36 to 42.  Students were given some time to work on Assignment 3.4 at the end of class, which we will take up tomorrow. 

Physical Science 20 - March 31

Today in class we finished up stoichiometry by looking at percent yield problems.  These are situations where you are given a certain amount of reactant and also given how much product that produces in an experiment.  Using stoichiometry, one can figure out how much product you should have produced, but due to experimental design and setup, these values are always more than what the experiment yielded.  We figured out how to calculate the percent yield of these situations.  These values should always be less then 100%.  These notes were covered on slides 26-30 in the notes and students then spent the rest of class working on Assignment C26 which will be checked tomorrow.

Physics 30 - March 30

Today we went over Assignment 3.1 and then started learning about Newton's Second Law of Motion.  This law tells us what happens to an object when a net force acts on that object.  It is also related by a simple formula which we will be using many times in the following days.  We then went through many examples and finished off with Assignment 3.2.  We went through slides 22-31 in the notes for those of you that weren't able to make it to class today.

Physical Science 20 - March 30

Today students wrote their quiz on Stoichiometry.  Afterwards we went over the answers to Assignment C25.  Students then spent the rest of the class working on the lab report for Lab C4.  This will be due on Thursday.  Tomorrow we will finish up stoichiometry by looking at percent yield calculations.

Physics 30 - March 27

We learned about Newton's First Law of Motion today, or the Law of Inertia.   After students took a couple of slides of notes (slides 16-17) we then looked at many different examples of inertia as well as a couple of interesting demonstrations of the first law.  There was no assignment that went along with this lesson.  Students can work on Assignment 3.1.  We will take this up on Monday.  Have a good weekend everyone.

Physical Science 20 - March 27

Today we finished Lab C4 by weighing our dry contents of silver and the leftover copper wire.  When students recorded this and cleaned up, we then learned about limiting reactants and how to determine them.  These types of problems occur when we are given a certain amount of each reactant and we have to determine which one limits the amount of product formed.  The one that does is called the limiting reactant.  This involves doing stoichiometry twice, with each separate reactant to determine an amount of a certain product formed.  Whichever reactant yields the lower amount of product will be the limiting reactant.  This was all covered on slides 16-24 in the notes.  Students spent the rest of the class working on Assignment C25, which we will go over on Monday.  Have a good weekend everyone.

Physics 30 - March 26

Today we started our third unit on dynamics.  We learned what forces are, general types of forces as well as some of the specific forces that we will be studying.  We also learned what a net force is as well as how to determine the net force.  A new type of diagram was introduced which was the free body diagram.  The FBD for short, will be a vital component to solving problems involving forces.  Assignment 3.1 was assigned and we will take up this assignment on Tuesday.  This was all covered on slides 1-15 on the new powerpoint in the Unit 3 folder.

Tomorrow we will start learning about Newton's Laws of Motion with an examination of the first law of motion.